As you imply, it is one of the most common tropes in bl, and yes we know it’ll pass and they’ll be happy again (or at least 95% of the times it gets better), but the fact that it’s such a repetitive and mediocre trope is what it makes ppl angry or bothered (cuz let’s be fr, miscommunication can easily be avoided or solved by sitting down and talking, so it being such a big conflict is kinda stupid.)
But it's so repetitive that you should just know that it's coming. For me it's like I just know it's gonna happen so it doesn't even fase me. It's just the cycle of BL, cool if it doesn't but that's rare. So people getting mad over it just think "oh this one won't have it" then get mad when it does. It doesn't make sense.

People angry about miscommunication and the adding of a love rival like you've never read BL before.