Some dealers are really good at subtly suggesting things like a warranty can be voided if you don't bring the bike back to them for service. Some of them aren't so subtle. Some buyers are under the impression that, by taking their bike back to a dealer for service, they're somehow "greasing the skids" in case they ever do need warranty work done on their bikes, or that they have to take it back to where they bought it in order to have warranty work done. None of that's true.
Shops don't want to do work when you, the customer, aren't the one paying for it. Some years back, I had a Hyundai that was in for a service and was told the subframe was rusting out at a critical point. Naturally, I was given a four figure repair estimate for it. So, I start doing some online research and found out my Hyundai was the subject of a class action lawsuit for the deteriorating subframe (they failed to put drain holes in the subframe, and salty water from states with winter and road salt was accumulating in the subframe and destroying it). My friendly local dealer, to whom I'd always taken my cars, refused to repair it under the recall, claiming that my car wasn't part of the recall since it was registered in North Carolina. Never mind that the VIN clearly identified my car as originating in the Snow Belt. It took several calls to Hyundai's US corporate headquarters, and getting right in the service manager's face, until they acknowledged that yes, they had to repair it at no cost to me.
That solidified the mantra that I've lived by ever since: "Dealers are not your friend". That doesn't mean they're your enemy, but it does mean that if they think they can squeeze a few extra bucks out of you with scare tactics like warranty work, or trading on your potential ignorance (like telling you that your 600 mile service check includes replacement of your spark plugs and a valve clearance check), they'll do it.
There's no sin in not wanting to do your own maintenance; you don't have to turn in your Man Card if you don't want to do it. But right there in your owner's manual, it lists everything they do on a 600 mile service (and at every service thereafter). If you just read that, and know what's involved, then you can call BS on a service manager when he tells you some nonsense about that service. If you sound like you know what you're talking about, a service manager might be less inclined to blow smoke up your ass.