The man is a giant...
...so it is hard to argue with his views, but, as has been pointed out above, the QL was amazing for its day and its price point, and was intended more for business than general purpose use. We forget the old RISC/CISC wars these days, too.
And while Linus and his mates must see the most astonishing varied set of hardware, it's hard to agree with him about the Pi being a toy. It's being used in that general purpose way, which is really the "open-ness" he talks about with the x86. Having recently moved a home/small-office server from an atom-based system to a Pi3, from a user/sysadmin perspective there is little to choose between them, and performance is by no means at toy levels. You have to get over learned assumptions when doing this, such as USB-hung disks, but the fact is it works and works well enough.
Rather, I suspect, he points out that the Pi represents a step of adequacy, where the IT world in general represents "progress", defined by faster, more, bigger. He makes that point when talking about designing down to IoT. If he is right, and the IoT become more like general purpose machines, we're in for a lot of trouble.