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.