Nothing to do with being male or female, just seen to be excluding trans people from being equal and worth a mention?
Really, that's your take? After seven pages of comment explaining that not including a group you don't belong to on a t-shirt featuring the name of a group you do belong to does not in any way imply anything of the sort?
Once again, just in case you haven't RTFT:
Certain policy aims of trans rights organisations do not align with certain policy aims of LGB rights organisations. That's why you have separate trans organisations in the first place. Because a growing number of LGB people are concerned that the policy aims of the former group are now being prioritised over their own and to their disadvantage, and finding they can no longer advocate for those LGB aims within LGBT organisations, they have formed an organisation solely dedicated to pursuing LGB policy aims.
This isn't about rejecting equal rights for the other group, but for making sure the needs of your own group aren't forgotten.
As to a t-shirt about your own group implying all the other groups aren't worth mentioning, surely you can see that doesn't make sense?
You wear a t-shirt like this coz you're showing this is my tribe. Tomorrow you wear a t-shirt showing this is my music, the day after this is my party, my football club, my country etc. It's not about the worth of others, it's about your personal preference which doesn't have to take into account the hurt feelings of everyone not mentioned on your t-shirt.