Quote: As for why you need to be in the special "remote" mode in order to use the remote, I would assume that listening for remote signals might drain the battery. Or perhaps TV remotes and other IR devices might accidentally trigger your shutter.
Exactly. If remote was set as default then imagine the posts from users wondering why their camera fired without them pressing the shutter!.
Given that the remote is not specific to each camera and there are plenty of 'universal' remotes out there and that the code may be the same as many other appliance remotes then the potential for unintended triggering is possible.
Best that the user has to
choose to enable remote and thus is aware of its being set than a whole lot of users unaware and assuming a fault.(well done Pentax)
As a side note the universal remotes such as this one have buttons to fire several brands of camera.
DealExtreme: $3.97 Jianisi Universal Digital SLR Remote for Pentax / Nikon / Canon / Konica Minolta
The possibility of mischievous use amongst a group of photographers at an event could be interesting, especially for those with remote capability enabled.