Nah. It'd be like if everyone just assumes that you like pop, because most people do. It might be understandable, but people constantly assuming you like pop and only pop is... tiring and annoying. Imagine if whenever you talked about music people would say "oh who's your favorite pop band?" and you're not even interested in pop. Or maybe you are, and sometimes you also want to talk about metal, but you have to be careful who you talk about it to, and if they didn't already know it's a whole thing. Etc etc.

You don't assume people like pop, even if it's the majority. You ca do the same for attraction!

Also, on a personal note, it definitely stopped me from figuring it out wayyy earlier than I could have. "Normal people are straight, I am normal, therefore I am straight" was effectively my reasoning (turns out. I'm bi and that's still normal. But go and convince kid me of that).