As an old school "biker" whose formative years were spent with oily fingernails and spanners in my pockets I too was initially amused by the thought of someone taking their bike to a dealer to have the chain adjusted, but thinking about it I'm not so sure I'm not the one off the normal spectrum these days.

Time was when bikes (and cars, but bikes more so) were hugely maintenance dependent and you were as likely to be changing a piston or a valve at the side of the road as you were adjusting the chain. Bit by bit the manufacturers have removed the weak spots to the point where there's not much the average owner is expected, or really needs to know about the mechanical side of things. I suspect many "weekend" low mileage bikes don't need their chains adjusting from one service to the next and, like much of the rest of the bits under the covers, can be ignored.

Part of the problem with the "no user maintainable parts inside" approach is the old Colin Chapman (founder of Lotus cars!) quote of "if I made it adjustable they'd adjust it wrong". Adjusting a chain does actually require a reasonable knowledge base as well as a number of tools to carry it out. You have to know that "as tight as possible" isn't the correct answer but if you're starting from scratch why would you assume that it has to be slack but just not as slack as it is. Years ago you could probably have picked up a copy of Motorcycle Mechanics magazine who would have walked you through the procedure step by step but they saw the writing on the wall years ago and reinvented themselves as Performance Bikes. Not much chain adjusting info in the last copy I read.

Of course it's an ill wind that doesn't blow anybody any good and reducing the knowledge base requires to ride a bike as a weekend hobby does give the dealers some chance to pull back an income stream lost when fitting new Norton crankshafts and fixing Triumph oil leaks were day to day jobs. If you can adjust your chain, rebuild your wheels or weld up a new frame think yourself lucky to be able to, but what else could you have been doing instead.