for a straight woman to say she's feminine and yet her femininity is not good enough for her so she needs to conceptualize her femininity as a stereotypically gay guy, and the stereotypically gay guy experiences his femininity as a straight woman (when he's 5 minutes away from transing). It's clearly all cultural and i understand why some damaged gay child would experience this but why would a straight woman?

Some straight women really feel that gay male femininity is superior in some way to femininity in women. Maybe part of the appeal is that the man can take off his costume (in the sense of drag, or even just remove makeup/feminine clothing; I'm just talking about performative aspects of femininity here) at the end of the day and be naturally masculine (compared to a woman). I'm picturing a regular guy in sweats with no makeup here. Another appeal may be the fact that despite the fact that femininity in men is often demonized, a suburban, slightly sheltered young woman/girl (these gals tend to be young or occassionally a little slow and mid-30s, but I haven't seen them much older than that) who doesn't know any gay, especially feminine gay, men may not understand how hard it is, but she can turn on the TV and watch RuPaul's Drag Race and think being a feminine gay guy is just one big dramatic, fun party.

As for the ones who do have a little more insight into the struggles feminine men face, they may learn that from church and/or existing around poor people (gender roles ramped up in those communities), and in that case see being a feminine male as someone rebellious. She may feel that being that person is the "fuck you" she's always wanted to say to her parents/pastor. All of this coupled with the fact that femininity for women is generally a banal, semi-mandatory, uncomfortable part of one's existence (at least in my experience, but the banal part is probably relatable to most women) as opposed to some rebellious "fuck you" catty drama party in the highly exclusive VIPs only rainbow badge gay club which they so desperately desire to be a part of.

Then, of course, the AAP, which I already discussed a little in another comment. I feel the fetish aspect, while intertwined with the cultural aspect, is much less complicated. You nut to the same thing repeatedly and with increasing intensity (escalation of shock/horror/disgust/novelty of content), you get a paraphilia. Most trans-id females are AAP, and most feminine trans-id females have AHA (autohomoeroticism; fetish for pretending to be a gay man). Their affinity for femininity appears to be tied to the humiliation aspect. They want to be the bratty bottom, saying "fuck you" to mom, pops, and Father by being feminine (and of course they also enjoy being feminine, or they wouldn't go to such lengths to continue to be so), and they also want to play the "feminine role". Yep. Getting fucked by a masculine guy.

As far as why these women feel they are "experiencing attraction to men as a gay man", they don't know how gay men experience attraction. They get ideas from yaoi and believe they're true, which vary, but in general they mean playing either the masculine or feminine role, usually the feminine one, but that also varies. I could get into specifics here but generally the difference is want power == masc, no want power == femme, but they like to switch it up a little sometimes. For example, a feminine-looking trans-id female who wants to be a "power bottom" (and probably only knows what that is from memes and porn) and likes to think of herself as a martyr for this cause: "not all femme guys are weak! we can be strong too ;)" but yes, in a perverted way, because like I said, their ideas come from porn first and foremost. Generally all of these identities are sexual in nature.

I'm not a man, but I think the male version is pretty analogous, just swap the feminine traits/expectations for masculine ones and there it is. I could write out a longer explanation of the male version and other things in more detail, but honestly I could just keep writing about this topic forever once I get started lol. Let me know if there's anything you want me to go into specifics about.