Yah, but I think that is an issue with all grills. Aside from a few parts on relatively newer models, it just doesn't pay to stock the parts. The demand is too low. I think many, if not most grill buyers look at grills like they do ovens. Once you start needing to replace stuff, it is time to move on. That sounds like heresy on a forum like this, but most of us live in a different world. Just think of the average joe that realizes he needs new burners. You basically have to dismantle a grill to swap them out. Just like changing brakes on a car, that just won't happen with most owners. By the time the burners go out, likely they are using a match or grill lighter to start their grill, the flavorizer bars are caving in, the bottom of the grill is so full of gunk that you have long forgotten that you even have a drip tray on the grill and the cooking grates look more like aluminum GRILL GRATES due to being so gunked up. "Honey, I think it is time for a new grill, lets go to Home Depot this afternoon".
Believe me, I pick up a couple dozen old Webers each summer to rehab. Most of them definitely have life in them with just a simple cleaning and replacement of the internals, but people just are not into that or don't think it is possible.
Another thing is, buying genuine weber parts gets to a point that it doesn't make a lot of sense to fix up the old Genesis. Most grill owners just go with weber brand parts because they don't even know there are aftermarket sources or want to research which will fit his grill. It can cost well over $200 burners, economy enameled flavorizer bars and economy enameled steel grates at an ACE or Home Depot. So, people just move from the parts shelves to the new grills being displayed right behind them.