Well, you do get a ton of tax breaks for owning an NBA team lol.
You are absolutely right that owners do it for ego. If winning 40 games and/or making the playoffs strokes his ego, well it doesn't matter what you or anyone else thinks. People need to understand the reality that their goals, especially when they have no stake, are not aligned with everyone else's. Not every owner is enthusiastic about waiting several years for things to develop. Vivek wanted to play 4 on 5 defense and stole that idea from his daughter's basketball team. He is not the same as someone who knows a handful of guards from the Euroleague who might fit into an NBA rotation.
I'm not saying this was a good move...just that 40 or 45 wins can mean something very different to different people and franchises.