A while ago I listened to a podcast [1] where the guest Stephan Kinsella argued that the state justifies taxing and regulating corporations by granting them special rights like limited liability. The guest then continued to explain that this justification is flawed since the these supposed special rights are actually not special at all. The argument made a lot of sense but it only explains the justification and not the reason for corporate taxation. In my opinion the reason is obviously to increase the state's control over us.
[1] http://www.stephankinsella.com/paf-podcast/kol-026-freedomai...