IT professionals are problem solvers by nature. They tend to swarm around a problem. It is normal, I enjoy the help.

I once had a client put my desk right in front of his so he could watch over my shoulder. I don't mind that either. I burned through his todo list in 3 hours, he moved me to an office.

Many commenters have already pointed out that the basic issue is trust. Give trustworthy estimates and hit them. Then if you feel micromanaged, you can point to your track record and ask for earned trust.