I rebuild, at least top-end during winter months. alot of guys, like you said(BDI) rebuild more often. I know of some rebuilding three times/season. It really is cheaper to replace piston and rings and not cylinders and cases. Weiseco pistons have been good to me also. Aluminum piston is softer than cylinder, so more wear and damage happen to it instead of cylinder, and I believe has better design in piston skirt. I also ride with some guys who refuse to fix anything till it actually breaks. Riding wore out pistons and bearings cause plenty of problems. Its much easier to tune fresh motors and it won't leave you sitting at the truck, while your buddies are out having the time of their lives.
My own disaster happened this spring after rebuilding my k5. I bought a basket-case and spent plenty to catch up with neglect on the 500. Took the bike down to frame, powder coated it, replaced everything that might be an issue, but overlooked carb slide. On the first kick, the slide was open about 1/4 " or better and it sounded like it was wide-open. The fresh rings heated up instantly and caused enough fire that I could not kill the bike. It melted down in about 20 seconds. I felt like I was sick for a week. Luckily my motor-guy was sympathetic and put a rush on the re-rebuild! If a pre-teen can kick your bike over, you need some compression guys. Keep the Kaws on top!!!!!