Posted by: Waterbird on Feb-15-13 9:57 PM (EST)
One way to think of it is that the terms "one- person," "two-person," etc. indicate some general measurements rather than the recommended number of people. A 2P is generally about 50" to 54" wide, for example.
Very few backpackers who backpack alone use a solo tent. I'm guessing that 90% of solo backpackers use a 2P. For a kayak camper, the weight and bulk difference between a 1P and a 2P are insignificant, yet you gain very valuable space with a 2P. For a backpacker saving 2 lbs might make it worth giving up the extra space but most don't want to make that sacrifice. Kayak campers just don't have a compelling reason for the sacrifice.