Firewall off when on LAN?

Hi guys,

What is the argument for leaving on the SEP firewall when you are on your corporate LAN and behind the corporate firewall?

The argument to disable the firewall would be to reduce complexity and any potential issues with some applications, but why would this be a bad idea?

Location awareness is in use when off LAN (i.e can't connect to management server) to then enable the firewall, so remote users are still protected.

Cheers,
Sam