Great OP. I've been silently disgusted with DLC for years now.
What I am ok with - Souls DLC, expansions, new areas, bosses, weapons, armor. Hell, I'll even go so far as Asura's Wrath DLC. At least there was actual content there, despite them holding the true ending hostage.
What I am not ok with - Street Fighter V "season pass" that doesn't even include everything from the season. Costumes only attainable via real money, instead of the in-game currency like they originally stated. DoA costumes that in total equal like 5x the cost of the game.
I agree with a lot of your points, especially that publishers will push as far as they can until they get a significant pushback from consumers. I feel like Microsoft specifically is the worst offender of this in all of gaming. The shit they've done, tried to do, or are trying to do always reeks of "let's see if we can get this one by them!"
Anyways, great read, and I wish there was a way to reverse a lot of these practices, but I do understand what some posters are saying about increasing costs with the same base game prices creates a need for supplemental revenue.