Why assuming someone to be hetero is worse than assuming someone to be lgbt+ 
A thread

A thread
I wanna point out that I'm talking about the assumption to be worse than the other, and not the sexuality

Also English is not my first language so if this sounds weird or unnatural at some point I'm sorry

First of all assuming someone is straight feeds to heteronormativity and is the reason why queer folks are still scared of coming out even in 2020. Whereas assuming someone is queer gives them the reassurance that they are loved and accepted regardless of their gender/sexuality.
Rn we still live in a society where the assumption of someone being straight is still very much common and it's more of a surprise when queer folks come out and that just shouldn't be the case.
Queer folks will often "assume" their favorite artists or celebrities to be queer because it helps them to feel included and reassured and it also reassures the artist that them being queer won't change the way they're perceived by their fans.
To put it frankly being a cishet never ever put anyone in actual danger. Cishets never had to worry about coming out (bc they didn't have to), cishets were never kicked out, attacked or murdered for being cishets. Meanwhile this is lgbt+ folks' everyday life.
If you get offended at gay assumptions you are probably lowkey homophobic. Lgbt+ folks have been fighting forever for what cishets have, assuming someone is gay is the equality that they want because they've been assumed to be cishet their whole life.
And as long as heteronormativity is still a thing the assumption of someone being lgbt+ will never ever harm a cishet person whereas assuming a queer person to be cishet is actually harmful.
If an artist "turns out to be het" it will not harm them in anyway, they won't get hate and their career AND life is not in danger, especially not from lgbt+. But that will be the exact case if it was the other way around.