those are "pools" not miners so they don't exactly control the mining power and the network. the minute they start showing any shadiness miners are going to pull their hashrate from their pool and move it to another place. not to mention that it can have legal precautions for them.

as for the topic of ASIC resistance, go ahead and introduce another algorithm that is superior to bitcoin's PoW first and then talk about changing to that. but as long as you don't have that algorithm, discussion about such change is moot.