Just take a moment and look at what's going on here. The woman simply posted a description of the type of person she is looking for, and now there is an entire forum thread dedicated to it. She doesn't owe anyone any type of explanation for her own personal choices. "CIS-only" isn't the only quality that was listed. She is also looking for someone who is lesbian, as well as monogomous. Is anyone questioning why she isn't also looking for a male, or maybe even a cheater? People have their preferences, no matter if you disagree with them or not.
If anything, it's a good thing that she stated up-front that she is only interested in CIS-gendered females. This way, people looking for a match can review her post, see that they aren't a fit, and move on to the next one.
