Much of "what happened to Rolemaster" (or in a greater sense, ICE) is a mixture of factors.
Two issues are the decline of the RPG industry as a whole, again for a variety of reasons.
1) Card Games and MMORPG's (Massive Mulitplayer Online RPGs).
a) Card Games created a way to play a quick 'game' between only two players that appealed for various reasons. Game companies, once they saw what was going on, realized this was a huge money maker and the method "took off" as it were.
b) MMORPG's gave gamers a way to play without having to gather up the group and presented an option that required no tracking, physically leveling characters, looking up rules, etc, etc. Basically, in the eyes of a lot of gamers, a wonderful option to table-top games.
2) Game companies were, by in large (WotC being the one exception) pretty small operations. After WotC (which had as many as 1000 employees) the next biggest company was maybe 5%-10% that size. Things as minor as the price of paper could harm their bottom line. Then there was the UPS strike which killed a surprisingly large percentage of the game companies out there.
Now RM was (and usually still is; part of what they need to overcome) considered the "Veterans" game system. While I am sure this is not what was envisioned by its creators, it was for the very experienced gamers who wanted 'more' out of their game system than the others were providing. It was (and is) often criticized for it's number of charts and tables and accused of being nothing more than a bunch of page flipping (these are usually the ones that come up - often from people who really don't know much about RM, or are possibly just poorly organized gamers). So, you effectively had a minority portion of the target audience of a small industry.
Two issues harmed the original ICE to the point that they declared bankruptcy.
1) Tolkien Enterprises. Without going into detail or the reasons why they pretty much intentionally sealed the demise of the original ICE. Middle Earth was a godsend for ICE and it was an albatross for ICE. It is, really not even arguably imo, the best
Fantasy license you can have... but it comes with having to deal with Tolkien Enterprises (not to be mistaken for the Tolkien Estate) which, again without going into detail, has some serious drawbacks. I don't speculate too much anymore on the moral side of what went down, because I see it from a unique perspective - both as a fan and as someone who understands a couple of the motivations for what happened. 'Nuff said.
2) This one can be debated, but lets just say 'in my opinion' (and again without going into detail), poor management. 'Nuff said there too.
So ICE goes bankrupt, gets bought by the second incarnation of ICE. So a second tier player in a small industry, which is in even worse shape than before, struggles along for a decent length of time. Most game stores, when you ask about ICE products, say "Didn't they go bankrupt?" Essentially, between the fact that the industry is in even worse shape than during the first ICE, and the same #2 above, they eventually lose the rights to most of what is considered "ICE".
Now you have the third generation of ICE, essentially being run by the former freelancers and fans of the first two as a secondary 'job'. While this is an improvement from my perspective it is going to be slow going. The success of the "current ICE" is largely going to be in the hands of it's current fans - not just in that they need to buy it for it to be viable, but in that they are likely going to be the main driving advertising for it.
If RM or HARP can be licensed to a online game, put out some computer programs, or maybe get a popular enough setting to put out a card game things will probably improve greatly.
What I am hoping for is a 'virtual game table' in the future.