Daim you refer to 'purist' lesbians and trans sexuals.
I don't agree with them being 'purist'. I find the word objectionable tbh. They are simply trying to asset their own identity rather than have someone do it for them. They want to set their own boundaries without prejudice.
The point of self ID was supposed to be that people could ID the way they wanted. But there is an inherent conflict in that; the concept does so at the expense and ability of others to do the same.
Lesbians have long felt used and imposed by bisexuals who are 'tourists' rather than fully committed to just women. There is emotional pain in there and the idea that they were just a 'sexual toy' to be played with, with never any long term commitment involved. Bisexuals who aren't honest about what they are, add to this sense of betrayal as they don't respect lesbians for what they are and actively use them. This makes it harder to trust and harder to form emotional attachment for fear of betrayal.
They are now being told that their freedom to choose to stick to 'purist lesbians' for other reasons is no longer valid. They are bigoted for even expressing any type of preference not to put themselves in a position they don't want to be in. It's not hard to see how they feel this is another infringement on them by bisexuals and this time men is a problem. This time it carries the risk of pregnancy and potentially even the risk of male violence. Things that have never been part of the equation of being a lesbian.
You are lesbian. That's fine. You obviously don't see this in this way but it's some feel.
Don't refer to other lesbians as 'purists' for this.
There should be a freedom unfettered from pressure to make that decision. You say you are getting pressure the other way, but I have to make crucial point here; Your personal boundaries are not under threat and that makes all the difference in the world.
Where 'purism' is coming from is a feeling that necessary to self preservation: of identity, emotional hurt, the physical risks of pregnancy and the risk of being exposed to male violence.
Refering to this a 'purism' is rather belittling and fails to understand how much comes from this desire to self preserve. If you have to use a word 'Isolatists' might be a better word. The key point in that word is that it's not maliciously infringing upon anyone else and is focused on self preservation. Yet this is reversed by TRAs in language and in the ideology as 'exclusionary' as if to suggest it's about superiority and hatred. And people have swallowed and accepted it without thought. The more it's pushed the more lesbians feel the need to defend themselves or isolate themselves in some way.
This is best highlighted by absence of lesbians from LGBT organisations. If they were truly exclusionary the campaign wouldn't be 'get the L out'.
Not being part of that, even as a lesbian, puts you in a position where what you believe means other lesbians will find it harder to distinguish you from someone who is bisexual. Thus you will be treated accordingly and will be challenged over it. Sometimes somewhat harshly.
The intent of some TRAs is undoubtedly lesbian erasure where no lesbian is free to exclude. That is rape culture if lesbians are not allowed to set their own boundaries. If you are happy with your boundaries of what you define as lesbian that's fine, but everyone else needs to be happy too.
There is nothing 'purist' about doing that. Emotional and physical attraction is something innate and isn't ruled by ideology. Ultimately you are not a 'purist' if you have a certain taste for someone who is fat, thin, tall, short or any other physical trait. You just don't like it. And that ok. You can't change it and you should not have to, just because someone else objects.
I find your use of the word really betrays what you are misunderstanding and misinterpreting. And not being supportive of the position of other lesbians who are in that position actively helps to endanger their boundaries. Supporting them does not affect your own beliefs or boundaries.
To put it most bluntly, not supporting them them feeds the entitlement of others to do what they choose to lesbians against their will.
If people challenge you as a lesbian, this is what they are challenging you on: a failure to adequately understand and defend the importance of boundaries always being a personal choice and this failure is enabling coercive language and behaviour to prevail.