Earlier quoted context omitted.
How is this a self-own?
It's just hilarious from the outsiders' view. It's just a bunch ppl want to insult but don't want to say the exact words.
The people saying Let's Go Brandon are perfectly happy to say Fuck Joe Biden. That's how the whole thing started. A large crowd at a televised NASCAR race started chanting it in unison whilst the winning driver called Brandon was being interviewed. The words they were saying were perfectly audible, but the interviewer tried to claim the crowd were not saying "Fuck Joe Biden" but rather enthusiastically chanting "Let's Go Brandon".
https://youtu.be/u9UjgITXUJ4?t=60
This immediately became a meme because it's such a perfect shorthand for the duplicity and accountability-free manipulation of the US media.
That's why it became a conservative meme in the following months. But of course because the media don't tell anyone where it came from or why, the people who get their information from it now believe that it's a "hilarious self-own" and people saying it "want to insult but don't want to say the exact words"!