So to say that they weren't excited to work with D&D - in your case - is a severe misunderstanding of what D&D actually is, and therefore bullshit.
If you decide to call someones opinion "bullshit", then you show more of your character than you might want to and you don't really encourage others to interact with you. Just saying.
Forgive me @Blackheifer but it seems that if you are going to dismiss my statement as bullshit - a statement that was backed up by a quote from Larian - you should feel obligated to do the same. Where is your evidence?
I frankly don't have the time to pull up every instance where the Larian CEO indicated he didn't like DnD but, from memory:
- he doesn't like that you miss so often in DnD (in the DOS system missing was rare but enemies had a huge store of hitpoints)
- he doesn't like that character level and spell level are different
- he never played DnD and preferred some other RPG whose name I forgot
- didn't care for the BG series and was more into final fantasy
- the infamous "we produced a 5e version of the game but decided it wasn't very fun"
And, of course, we have the CEO's recent statement. Larian wanted to things in combat that would violate DnD rules.
While your characterization of Hasbro - low effort, spreadsheet minded - is correct I see no evidence that they were behind the death of the DLC. I'm happy to hate on Hasbro but I think I need a bit more than Hasbro eeeevol to go on.
To underline this point: I don't want to carry water for WotC but I don't like conspiracy theories either.
As to why they wanted the contract and tried to get it twice? Everyone making RPGs wanted to make BG3. It's the flagship. It's the name that brings in money and brings recognition They wanted to contract to make money and burnish their reputation. No fandom required. Duh.
I don't think the ruleset restrictions is the only problem but all the other decisions they made. They wanted to add a lot of traumatic topics like SA but failed to handle it with the needed care and sensitivity.
To me personally (and I'm saying that without any evidence) it feels like they aimed for a big shot to gain popularity, to be a part of the holy grail and in doing so, they never even asked themselves if their were capable of doing so or if they maybe couldn't keep it up for the time needed. In addition to that, the fans they attracted (especially all the fans that bought the game based on all the bear sex and Dark Urge violence news after last PFH) have proved to be way more fanatic and obsessive then they maybe even expected.
I can see the team burning out after all the feedback, the threats and such - thus adding to an already questionable state of the team.
Again, this are just my thoughts, I don't have any evidence but I try to take a different approach than just "Larian good, Hasbro evil, accept it or leave".