Even without SP DLC, it's been said for years citing feedback metrics (and yes trophy completion percentages) that players are done with a game when they are done with a game - not when they reach the end, or do x percent of the gameplay, or whatever. When they're done, they're done. It must be frustrating for developers to witness this with their own games.
But DLC doesn't have a reputation by accident. LA Noire's season pass (the first to be actually called "season pass", I believe) was ripped out of the main game. So was Assassin's Creed II's DLC. Players were tipped off by dialogue oddities and sequencing when woven into the main story path. And other content has been partitioned for DLC purposes, particularly whole characters in Dragon Age Origins, Dragon Age II, and Mass Effect 3. People still remember this, and vestigially the feedback surrounding the RDR2 "people missing from camp" bug is a reminder that a cohesive-feeling experience is still important to people who play games.
As for such feel, Shadow Broker definitely "felt" ripped out of the main game, as it had such a crucial character arc and story plot point. As did Mass Effect 3 Leviathan, and AC Brotherhood's DLC. And I'm not saying things were ripped out or partitioned on purpose like the above, but the feeling you get playing it is that its inclusion in the game makes the experience cohesively very much more complete, and in hindsight is less so without it. People don't want to risk getting into something that will give them the experience of low cohesion, or feel they have to pay extra just to experience a sufficient amount of cohesion at that.
But Frozen Wilds and Witcher 3 DLC didn't feel ripped out of the main game, at all. Neither did Left Behind. And other Assassins Creed DLC really is extra, since the content is separate enough from the main games' offerings. DLC that went solo like Gay Tony, Freedom Cry, Lost Legacy, Death of the Outsider, etc. earned their worthiness as standalone titles, which has brought some goodwill and reputation increases from early in this decade.
God of War 2018 seems to have avoided this whole debate, and even offered some QOL updates that some titles offer as part of extra DLC (BOTW is one recent example of QOL features being offered in an expansion). But overall it seems that like players, when THEY were done, they really were done. People may be left wanting more, but they also understand what it means to be done with a game.
Spider-Man DLC I'll be getting soon, so I'll find out then.