I don't what "real computing" is if it isn't writing a novel, a piece of software, or working on a spreadsheet to run a company. People do all these things on laptops. Some people actually like touchpads; others plug in USB mice; keyboards vary, as do most people's taste (ergonomically, your keyboard is probably worse than a laptops if you're right handed - the long reach for the mouse caused by the num pad is a big cause of trapped nerves and RSI.)

Lots of people buy a machine that's adequate for their needs for the next three years then throw it. This works. As for "no power", i'ts hard to buy a laptop these days that isn't adequate for everything short of cutting edge videogames. Or running Vista.

I think you'd probably be even less comfortable with a desktop system on your legs. The point is that with a laptop you can use it on a desk - or airline seat tray, coffee shop table, etc - when one is available.