True to an extent, but that doesn't seem to be the main reason why lesbianism has been looked down upon (when attention is paid to it in the first place). It seems to go back to violating cultural views of masculinity and femininity from what I can tell from the historical evidence.
This.
Also lesbians have long been fetishized as existing for the male gaze, insultingly. Perhaps less so anymore, but it’s still a thing.