The novels were a mistake and a dead end that WotC is not going down. Trying to force people to buy terrible slop in order to keep up with canon was both deeply immoral, and eventually self-defeating as the massive weight of canon became too much for anyone to keep track of. However settings may have been misused in the past WotC has no reason to go down that damaging path, and is only using the settings for their proper purpose, to support playing D&D.
Nope. Not even close.
TSR, then later WotC, published hundreds of D&D novels over decades. Some were crap, some were amazing, most were okay. The endeavor altogether was hardly a mistake, the novels did better than the games at various points.
And the novels never really stopped, although the output dropped significantly as D&D shifted to 4E then 5E. But Salvatore kept writing Dark Elf novels, and now we are seeing an upswing in novels again.
And, good lord, the intent of the novels wasn't to "force" fans to purchase novels to "keep up" with canon. That's a ridiculous assertion. TSR, then WotC, published novels for the same reason we get D&D comics, D&D video games, and other D&D tie-ins. Fans want them. TSR and WotC wanted to capitalize on that and make more money.
"Massive weight of canon nobody could keep track of"!?!? Dude, some fans live for that! And for more casual fans? It's just not an issue. At all.
The "proper purpose" of a D&D setting can be more than one thing. That's like saying Disney should ditch everything that isn't a cinematic movie for Star Wars (which, I'm sure, some cranky fans out there would argue in favor of).
If you don't like D&D novels, there is an easy solution. Don't read them. But try not yuck other folks yum. The novels were very successful, have a lot of fans, and are just fine.