If I tell you "I am a heterosexual woman (meaning, a woman who is exclusively attracted to and only dates men)." I am not restricting myself the possibility of dating non-men, because that wasn't an option in the first place. The label does not determine my attraction, I determine my attraction and then I seek out a label which accurately describes said attraction.
If you feel boxed in and/or trapped by labels, maybe try identifying what your attraction (or gender) is first, and then find a label which accurately describes said attraction/gender. Use them descriptively not prescriptively.
I also find it very interesting how this crowd only seems to emerge during discussions of lesbianism. As in, you're only anti-label once a lesbian is describing her exclusivity towards women. It's very similar to how the gender abolitionost crowd exclusively emerges during conversations surrounding trans women.
Could it be, misogyny? Transphobia? Cissexism? Homophobia? Lesbophobia? Transmisogyny?
No no, you just purely in good faith take umbrage with how lesbians and trans women (and trans lesbians) describe themselves, for no external reason.