A fun read...
Hammers a hot favourite for European football – West Ham 2019/20 Opposition Preview
https://www.thisisanfield.com/2019/08/hammers-a-hot-favourite-for-european-football-west-ham-2019-20-opposition-preview/
I don't think it's so ridiculous. The team was probably mid-table at the time. The club was due much more revenue - and cheap rent.
The fans started protesting a year or two back when the owners didn't spend on players. Then, when they did, they spent poorly - that's the key.
Belatedly, fans...
They were promised European football.
If the club was well-run and they were in a similar position to, say, Wolves, I'm sure they'd live with the stadium.