Your first point is spot on. x86 has been always backward idiocy has a big part of the chip is dedicated to compatibility with the past. Similarly a big part of the ARM processors is dedicated to video instructions.
The Intel architecture has a horrific trend in what touches security. You cannot do away with firmware signed by Intel. Similarly in some ARM architectures, namely raspberry PI, you are suffering from the same exact problem.
It is virtually impossible at the moment to design a product based in an Intel chip that respects your privacy.
You also have problems in lot of ARM boards where the code is sloppy hacked by the vendors, and you are limited to the kernel version they hacked, having a dead-end product.
MIPS has had always had an interesting architecture design, pity it has lot a lot of traction, and the Chinese seems to have abandoned the Longsoon project, at least for selling abroad.
At the moment, you have too spectrums of the market gaining momentum, ARM machines for low cost servers and private computing, and Intel for virtualization farms.
So pick up your poison carefully...