The arguments for BI that I've read here on HN assert that this isn't a problem, because people who don't want to be working are a net drain on the systems in which they work, and/or they will be replaced by people who want to work a little bit but can't because they will lose disability.

The incentive to continue working even if you receive BI is that BI won't be enough to have a luxurious lifestyle, just enough to meet basic needs and educate oneself.