Spiritual sequel to Saints Row, Volition barely marketed or even communicated what Agents of Mayhem was, let alone the specifics of its loot grind-heavy gameplay.
Still, "From the makers of Saints Row" carries a lot of weight, and you could tell that with the rise of "games as a service" like Destiny, The Division and Overwatch, Deep Silver wanted their own year-long cash cow. Thing is, the reason fans sink 500+ hours into Destiny is because of Bungie's immaculate FPS engine.
Agents of Mayhem... well, Volition are not Bungie, despite the prior Saints games still being fantastic. Making the game one big loot grind paired with basic "attack/defend X objective" missions was generic and rote at best, with some admittedly fun characters failing to save the project overall.
For every Overwatch there's a Battleborn or a Lawbreakers. Agents of Mayhem very much drew up a spreadsheet of "What's hot right now?" in regards to bankable mechanics, but executing on those elements with zero originality only ruins the appeal.