[pohl]

Why are we assuming that a tech conference should be anyone's sexual playground

Are you asking me? It's the site's premise, not mine.

As for their heteronormative assumptions (if any), must the site be prepared to service all markets before they're allowed to enter any one market?

Edited as per gte910h's observation below.

[gte910h]

I don't understand why you'd say they're assuming anything about the sexuality of the women that they're looking for. If anything the site is resoundingly silent on that, just literally mapping 4sq checkins to locations for people of the female gender who checked in.