it's not the same thing. first of all, straights dont get "hate" outside tumblr. gay ppl get killed, fired, thrown out of their homes, bullied, abused etc. sure, it's never okay to write rude stuff to people, no matter what happens to your community
if someone sent you a private message saying "hey cis scum, go die!!" that would be horrible, obviously.
but it's not really the same thing when a random trans person online writes out their frustration with cis people?? idk i'm confusing rn but aaa
But if someone 'writing out their frustration' involves spreading hatred for an entire group, it's not really any better than someone spewing any other kind of bigotry. Two wrongs don't make a right. Even if you concede that homophobia is worse than heterophobia, or misogyny is worse than misandry, you can still see that both are bad things, and it's right to call it out, the same way you'd call out someone throwing around offensive words like f*ggot.