I think the contrast between Musk's SpaceX and Twitter experiences is largely down to whether the organization grew up around Musk. SpaceX has an immune system built up for the nutty stuff, from Gwynne Shotwell on down. Twitter got thrown into the deep end with zero staff powerful enough or with the experience to do the post-idea cleanup work.
It's a huge mistake to say "Elon had nothing to do with SpaceX's success". It's also a huge mistake to say "SpaceX's success means Musk's Twitter plans are good".