its simple economics my dear Watson.
Outgoing salaries = $0
Incoming TV + merchandise + Gate Receipts + player sales = Many $$$$
Therefore $0 + Many $$$$ = Many $$$$
some people label this under the 'tanking' umbrella. Its basically just a quick way to make cash fast, and you are pretty much guarenteed to be getting a better chance at the early draft pick.
I personally dont see the point in this, its a bit hollow as you dont worry about team tactics, player trade movements, analysing other teams, so it reduces the overall point of BuzzerBeater - however some teams who have been playing this game for many a season see it as a way to demote and play the game in a different style that they could not experience unless they closed their account and created a new one. And thats their choice and maybe one day in a few years after im sick of constantly winning the ABBL ill probably tank and do the same.