I'm a developer and I hate closed proprietary ecosystems with a passion, so that was just lip service afaic. Current microsoft is much more "developers developers developers"

That's kind of the point, though? A lot of people make fun of Ballmer for using that as a repetitive mantra, but a point often to a mantra, to repeating it to yourself and others, is to remind yourself it is a value you hold, and one that you maybe aren't great at, but should continue to strive towards/get better on. Current Microsoft likely wouldn't have gotten better at "developers, developers, developers" if Ballmer hadn't been shouting that to the rooftops as a core company value, and trying to drive the company to be better at it. The irony that Microsoft got much better at it in part by ignoring some of Ballmer's other past paranoia/NIH/"home-team-ism" probably wouldn't be lost on Ballmer himself either, it always seemed like he kept repeating the mantra as a reminder for himself too to not get caught up in what seemed best to shareholders or to Windows when that wasn't best for developers. He wasn't always successful, but holding a value/ideal doesn't make you perfect, it gives you a goal towards it.