Why is accessing session through HttpContext.Current bad [practice]?

Question

I am trying out signalR and followed their Chat sample with a few modifications. So, in the ChatHub.cs, I tried to access the user's session variable and found out that I couldn't. So I've searched the web for answers and found this: Access to Session from a Hub

So as commented by Mr. David Fowl, accessing session variables through HttpContext.Current is bad. Is it really that bad that I should avoid using it? I really need to access the session variable.

Answer 1

I am guessing the reason it is bad is because your code will not work if hosted outside of the asp.net context. Since HttpContext.Current is web specific