My one paragraph answer is:
"The weak link was the Rotax 582 2-stroke engine, it was just too tempramental for the average Joe to sort it out. Yes, if all machines were maintained by Revolution, they would all still be flying. Once sold, the responsability went from trained professionals, to some backyard spanner macks. Not all could keep it from seizing up."
My other answer is: "RB, I know once I hit this "post reply" button, a storm of arguments will erupt. However, I will tell you my personal opinion of the whole story.
Firstly, Dennis tried, and succeeded, to produce a low priced helicopter, one that everyone could afford. It was simple, could be assembled in a very short time, a glorified Meccano kit ( no pun intended towards the heli kit). What happened next, is guy's with too much spare cash, and a dream of flying a heli, bought the kit on a Friday, built it on a Saturday, and tried to fly it on a Sunday. Now, I'm going to generalise now, it attracted a customer base that had no or little heli flying experience, neither a lot of aircraft building experience. With a heli, you can fire it up in your back yard, that's what a lot were doing.
Next situation, the new kit did go through some teething problems, the worst one being the 2-stroke engine it used. It was the best available at the time, better engines only became available much later. The Rotax 582 was prone to sudden stoppages. Yes, a big problem, but the company did overcome that issue as well, more about it later. Now, a low time heli pilot, with a machine that he had no dual emergency training in, most autorotations after engine stoppages did not make it. The famous one, the high time pilot killed, well, he most probably used his turbine type procedure, but it did not work. I bet you, put a high time turbine heli pilot in a Robbie 22, without practising auto's beforehand, and ask him to perform one, I bet most will fail it too. So, the low time pilots could not handle the emergencies. That's what you get if you just jump into a single seater heli.
By now, the product had a bad name, but there still was not a history of component failures causing the deaths. An engine failure does not mean certain death, the heli's could be auto'd. Yes, there were frame cracks at first, bearings packing up, but those were all corrected. They never lead to structural in-flight failures.
By now you had a lot of negative publicity, and a couple of guy's, with no Mini-500 experience, fuelling the fire of negative publicity. But take note, all the time, there were guy's out there, all over the world, flying them without hassles. Still today, there are some hardcore Mini-500 owners, keeping their machines flying. Flawlessly !!
Another problem that occured, the company was so busy with production, they did not spend enough time getting the fixes out sooner. Dennis might take offence here, but hindsight has 20/20 vision. So the negatives were piling up too fast. But go and research it, the AD's and SB's were all issued, adressing all areas of complaints, but guy's were not implementing them. By the way, go and check out Robinsons history, or Rotorway's history, same things happened, Revolution was not unique to these problems.
I think it was a flood in Missouri that forced Dennis to take a loan from the state SBA, to get the factory up and running again. This might have been the fatal bullet. At a critical time, when Dennis was expanding the design to a 2-seater, some of those negative people managed to convince the SBA, that Dennis was going under. Yes, he seemed to be under financial stress then, but he was funding the 2-seater. Yes he took deposits, but their products were going to be delivered, had he had the chance to finish it off. One day, the SBA walked into the place, convinced by some compeditors that the business was going bust, so they wanted their investment loan back. Dennis once told me, he was locked out of the factory at once. So, the company was broken up, the tooling sold off. Dennis never had the chance to make it work again. People blame him until today, that he stole peoples money, the deposits of the 2-seat Voyager. It's the SBA that are to blame, they closed the shop down, they did not re-imburse the depositors, Dennis was shut out of the business, he could not pay anyone back. Hey man, anyone that gives money to an investor, you have to give him the chance to make it work, not pull the rug out under him, while his working on it.
I still say, the Mini-500 is all what it was set out to be, an affordable single seat homebult heli kit. Don't complain about, for example, not having needle roller bearings in the control linkages, if you want that, go and buy a certified version at 100 times the price. If the buyers were expecting to get certified heli quality, for $25K of pricetag, it's their mistake. The same goes for gyro's, airplane kit's. The truth is, it flew, it still flies well, just a shame it is no longer in production. It was of sufficient quality, to be operated as a homebuilt heli. You had to do servicing, comply with AD's and SB's, things that some people did not do. They paid with their lives.
Another issue was people were judging Dennis's personality, not his product. I did not know him then, I'm forming my own opinion here, from reading all about his past. He was younger, and seemed to have a strong A-type personality. So what if he was like that, he was on top of the world, having produced a heli kit. It seemed this personality clashes became personal to some, and it boiled over in the product being dragged through the dirt. Until today, there are guy's that cannot wait to get the daggers out, when he says something. Unfortunately, he then responds harsh to their comments, making the situation blow up most of the times. Can you blame him for responding like that, having been verbally abused for decades?
So what killed it, it's the negative publicity, a feeding frenzy of jealous people. Today, with better 4-stroke powerplants being available, if anyone should ressurrect the production line, he'd make a fortune. If I had financial backing, I'd do it in a flash.
I have one, I'm as happy as a pig in Palestine with it !!