Is the SegWit2X success due to concentration of mining power? SegWit2X has been called a short-sighted &amp; severely lacking proposal. There is nearly universal preference for its alternative among those listed on the segwit support overview (SegWit, BIP 141,148,149).

Yet SegWit2X has 90% mining support.

Is this because the vast majority of Bitcoin mining / hashing power is concentrated in a few hands? Does this mean that those who control the mining power can get whatever they want?
I feel that the existing answers here fail to highlight that while (the collection of) miners have the authority to select the order of transactions, and impose additional validity rules, they do not have the authority to determine what the rules are.

Segwit2X (in my understanding, there seem to be multiple ideas out there) seems to be a combination of a soft fork (activating SegWit) and a plan to do a hard fork later (changing some resource limits). The first is something that miners can do, but the second will only be accepted by full nodes that implement the same rules, and be ignored by everyone else.