The key words are "a lot of people".
D&D hasn't been a niche game for decades now and the fandom grows by the day. Both TSR and WOTC wanted a wide net and designed a game for a lot of different kinds of fantasy fans.
The wide appeal means it is worse at honing down on specific tones and systems of fantasy.
What D&D does best is taking the familiar, twisting a few of the ideas, and adding ideas from the outside. If you want to play any genre, style, or tone straight, there are tons of games better at that than that. D&D is best at mixing ideas as it itslef is a host of classes, races, monsters, items, and other ideas from all over.
Hence why I don't get the heavy traditionalism in D&D's GM community. If you are have a style, genre, tone, or image you want to run over and over and have been for a long time, there are probably a better RPG for it by now.
D&D without a constant stream of spice just feels like a massive compromise.