Do you share your work in progress or only finished pieces?

On my Instagram I tend to share what I am working on, mistakes and all.

Weird thing is people who hardly ever like or comment will come out of the woodwork (heh) and DM me with unsolicited criticism or questions about how I did something.

It doesn't bother me but feels a bit weird - like why not post in public? Why only criticise?

Do you experience the same thing?