I actually don't particularly care for those kicks whether it be Anderson Silva or Jon Jones. I think it's dirty and probably should be illegal, but as soon as you make that illegal then the leg kick game becomes a mess where fighters that getting warnings for being to close to the front of the knee...unless of course the rule is that you can't side kick or push kick a knee.
I mean, how would anyone feel about this situation. Fighter A and Fighter B
Fighter A has fighter B down on his stomach. Fighter A grabs Fighter B's forearm and pulls up while driving his (Fighter A) knee into the back of Fighter B's elbow, thus breaking the arm at the elbow joint.
That's more extreme, but essentially the same idea. I just think it is a dirty move and shouldn't be used simply out of respect. You catch a fighter planting a certain way and land that kick, you could cause some serious damage.
As for the spinning elbow...