Intel is an industry leader. EFI, Thunderbolt, and the "ultrabook" product category are all their ideas. By adding a feature to their CPU products, they induce demand for anything that complements it.
By putting ECC support into their highest-end mobile CPUs only, they made them into high-end luxuries instead of industry standard. https://ark.intel.com/content/www/us/en/ark/search/featurefi...
There's nothing defective about RAM, it's never going to be the case that errors won't happen, it's just that before we were worried about heat and radiation and now we have to worry about attackers too.
Without a specification that says so, I don't think it's necessarily the fault of the manufacturer if they cannot build perfect RAM!
Suppose someone builds a car with one these computers in a safety-critical role, and then someone gets injured because of an error that "originated" with the RAM.
But if there are corner cases like this, they should be added to specs. Most likely it would require memory controller to remember last addresses and insert delays if rowhammer attempt is detected. And/or make CPU microoperation scheduler avoid it. No idea how expensive would that be, surely nontrivial.
At least on AMD it works these days.
ECC RAM is pretty effective as-is against rowhammer, and imo you could very likely tweak ECC's approach to get even further.
The 'worst case' solution wouldn't be more than 2x, right? Since you'd just have to keep a clone of RAM, but obviously shuffled so that the same errors wouldn't occur in the same places. So 2x seems like the sort of absurd upper bound, but I feel like we could do a lot better.