Is the stigma too great?

The absurdity of ".onion" is a subtle turn off, I think. If they'd gone with .tor or something more serious or less... lame, more people and business would engage. Naming is important. .onion is just stupid.

The name hints at how Tor works. Just like the Tor logo.

Another connotation I have is with Shrek onion scene https://youtu.be/-FtCTW2rVFM

Yes, and it comes off like a cringe meme, probably because of the Shrek thing. It's not something that suggests a sophisticated security tool. It's not even a good pun or play on words. The branding is just bad.

That's just in your head buddy, can't say I heard this opinion expressed before. Ever.

I agree with it, but I don't care strongly enough to ever say it anywhere.

The subject doesn’t come up much.