Or it could be that previous management was constantly prioritizing new features instead of performance gains and now he's getting unnecessary flak for it.
The worst thing is that by firing and laying off too many people on a team with so much legacy code, they might end up scrapping the app and doing a rewrite because it'll be easier than fixing it. So inevitably, it will run faster, and people will hold it up as an example of Musk being a "genius" . When really, it's exactly what the guy suggested doing, but instead of listening they fire him and force a situation where they have to do it anyways.