Interesting points brought up. There was a time when you had to be mechanically inclined to own and operate a moto.
Also, whats with shying away from suspension? I'd say it's easier to install new springs and do fork service than it is to do a valve lash adjustment.
Suspension isn't voodoo, tho I wouldn't rebuild a shock myself per se. Forks? Not a big deal, really.
Valve adjustments vary wildly. Some bikes require four bolts and a few minutes. Others require the bike to be 75% disassembled. Either way, I would/have done both.
Which brings me to my anecdote about a shop calling it good. Many modern bikes barely need adjustment after they've been broken in, so in many cases, you could probably get away without adjusting them for long periods of time.
Know a dude who brought his bike in for its first valve adjust (on schedule). Bike lived at the dealer for about a week and he paid a few hunnert bux. Got bike back everything seemed the same. Not that you should notice a huge difference, but to him it just felt too much the same? Intuition? I don't know.
Anyways, he axed me to help him check it out. We did and found that about half the valves were out of spec. Some tight, some loose. Radiator hose had obviously never been R&I'd. They didn't do jack diddly shit but charge hundreds of dollars for an oil change. Had the bike open, so we did it ourselves.
He went down there later and laid into 'em, tho their response was something like "duhrrrrrrrrrrrrrrrrrrrrrrrrr".
I have heard other similar stories as well. Not to say it happens everywhere all the time, but it does happen.