10 years isn't true. In the last few years, we have finally seen a successor to the RAD750, the RAD5500. And it's multi core finally. But rad hard technology does move at a glacial pace and is 10-20 years behind commercial.
Our problem doesn't have to do with radiation hardening. In fact, we don't even need radiation hardened cores -- our problem is actually due to design decisions that have been made in modern cores that sacrifice determinism for speed.
Maybe it is true for him. This isn't my area, but the Wikipedia article for the RAD5500 says it's for "high radiation environments experienced on board satellites and spacecraft," but the grandparent only a need for tolerance to "modest radiation exposure (avionics)." Maybe the RAD5500 is overkill for his application, and there actually hasn't been anything new (in his niche) for 10 years.
https://en.m.wikipedia.org/wiki/RAD5500
http://www.baesystems.com/en-us/our-company/inc-businesses/e...