Your assumption may be correct or it could be that it's simply what people are willing to buy that domain for with whatever their factors are.
It's uncertain with exact examples of bidding that you see going on.
You bring up it generating revenue, if it was a prior website, it very well may have existing back links generating organic traffic. It will soon be dwindled down, but that is the business model of some people.
There's a lot more to look at as to why a name has so many bidders over none.