Yes and no. It all depends in what field you're describing sound. In physics, a tree that fell in the forest most definitely made a sound. In psychology, it doesn't.

In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid.

In human physiology and psychology, sound is the reception of such waves and their perception by the brain.

https://en.wikipedia.org/wiki/Sound

To be honest, I'm with the physicists.

Nah, as long as you keep following recommended security practices it can be useful to get rid of unneeded load being put on your server by malicious bots.
I had a lot of problems with botnets hammering my SSH service on my private VPS. Moving it to a different port would only work for a few days before they'd be back at it again.

I wasn't worried they'd get in. But logging in to my server would take ages because it was under so much load (VPS is pretty low-spec). Finally decided to shove my SSH service behind port knocking. Got rid of all the bots knocking at my door.

Obscurity has its uses, as long as you don't consider it a replacement for security. It's just an additional tool.

I'm just a dude who doesn't have any background in art. So the whole terms of "line work" or "line weight" mean nothing to me.
What I see is just a nice little bird icon. And if that logo was used everywhere it would be instantly recognizable at a glance. So for me as a user of a platform it would do perfectly fine as is. Maybe it could be improved upon but I wouldn't be able to tell you how.

What I do not appreciate is how the comment you replied to presented their feedback on this. They might know what they're talking about (or not, this is the internet. Anyone can make any claims.). If this is supposed to be constructive criticism, I can confidently say they've missed their mark due to their tone alone.