The majority of the mining community and mining industry is the reason why they have that power.

The peak of that power was around the time the S9 came out, coz people choose to mostly buy BM hardware even though it was crap reliability and crap support back then.
They made it 'cheap cost' and crappy and most everyone wanted it, thus their rise back then to being the vast majority of all mining hardware.

It was only the internal BM fight that ended up being BM vs Poolin that managed to slow that down.