I bought my cb 750 K7 with F2 engine 5 years ago. This was my first bike. I didn't know how many miles the engine had on it, and I didn't have any mechanic skills, and I started using it as a daily rider (50 miles a day). Never had a problem with it, and with the normal maintenance, just adding oil due to the engine wear (valves and pistons), never left me on the road. Almost 2 years ago, I started rebuilding the engine, because since I owned the bike, I became more interested on mechanics, and learned a lot (a lot from this forum). I didn't became paranoid, but when I knew what an engine had inside, I decided to rebuild mine just to be absolutely sure that this would be totally trustable, that when I finish the rebuild it will be a 0 miles engine that can be used as a daily rider.
Anyway, IMO, the more simple something is, the less problems it has. An air-cooled engine, carburettors, simple electrics... is understable even for a person with basic mechanic skills, like me, and the maintenance is easy. I drive also a 20 years old car, a Peugeot 205. Some people laughs at me for driving such an old car, but it has never given me any problem...