Well Rambus did just come in and patent everything and then try and licence other company's tech back to them. It's pretty scandalous behaviour. Don't get me wrong, the other companies were just as bad fixing their prices to force Rambus out of the market.
My personal view is that Rambus still have some innovative designs, while the others sit around in committee after committee waiting for someone else to do the work. It's why all of the DDR specs are so middle of the road compared to what comes out of Rambus. I mean RDRAM was so far ahead of its time compared to SDRAM, it's just a shame it was so expensive (which we now know was down to price fixing rather than some inherent cheapness of SDRAM which we all thought lead to the situation).
To understand why the rest of the memory world is so dead set against working with Rambus, you have to know a at least a little about the patent system. For an idea to be patentable, it has to
A: be non-trivial. If the idea is at a level that someone "in the field" could reach by extension, or easy realization, it is not (should not be) patentable.
B: have "height". Again, the idea can't be to close to something existing or too trivial.
However, this means that what is patentable or not is up to the local patent office where you submit your application. There is no guarantee that the same idea will be treated the same even in patent offices in the same country, much less across the world. To be blunt, in the eyes of the rest of the world, the US standards when it comes to what level an idea has to have to be patentable is quite low. If something new comes up, you can quickly come up with a bunch of rather trivial ideas and effectively block the field. Furthermore, the US has rather odd litigation practises - if for instance Rambas wants to sue Toshiba, they can do it in some godforsaken hole with a drunkard judge, and that is where it will be handled. And Toshiba cannot say that they'd rather want the case to be handled by some kind of international patent court, such an entity doesn't exist. Anyone believe that for instance an Indian company, sued by an American company over a patent granted by an American patent office, in an American court has much of chance? It's a nightmare scenario for any non-US company.
The rest of the world is effectively forced to play by the rules set down by US patent standards and litigation practices, and we are not happy about it. At all.
I'm not sure someone born and bred in the US can understand the frustration of the rest of the (tech)world, and how abhorrent a company like Rambus is. Nobody has a problem with corporations developing new tech and patenting their good stuff for proprietary use or licensing, but Rambus is very artfully leveraging the (bizarre) US patent system and litigation legislation against the rest of the industry.
They are pariah, and ironically their methods is the one thing that has stopped a good idea that could have reached widespread use long ago. It's sad, really. Patent squatting killing something good. Then again, it's not the cure for cancer. I doubt that the lack of uptake has made any difference in the greater scheme of things. But damn, in this day and age, patents need to be handled at an international level.