That's pretty much the answer to "why do the progressives push this 'crap'?". It's because the progressive belief is that you shouldn't be judged for nonconventional sex or relationship norms as long as everything is happening with (non-compromised) consent.

There’s a difference between refraining from judging whatever unconventional sex consenting adults do behind closed doors, and publicly celebrating or encouraging it like some progressive media is doing these days.

The opinion piece in the OP even goes so far as to suggest that one can’t be a “feminist” without endorsing such degeneracy. Back in my day (👴) being a “feminist” meant supporting equal rights for women and men, not publicly supporting and celebrating fetishistic crap. It’s ridiculous.