Money is fungible. Every single dollar that goes for Twitter is exactly a dollar that does not go for what he used to say was important.

He might be heard to say those again, but dollars speak louder than words. Musk can say anything, anytime. What he does with his money demonstrates what he believes.

By that same logic the US should immediately stop giving foreign aid to developing countries or investing in other programs since we still have homeless people here. The reasons why entities spend money on specific things is not a univariate. Also, there is a whole meta discussion to be had about what sparks creativity and innovation, I have a pet theory about over abundance of resources creating stagnation and dulling people's motivation and creativity. Beyond a certain point, throwing money at a problem can be counter productive.

At the end of the day, results matter and SpaceX has shown results.

"does not go for" 0 nope all of his share holdings are just that, holdings. It's not until he liquidates any of those shares that the money be put to work. In that way it doesn't matter he he shifts billions into twitter, he can liquidate it just the same. Probably for more given his track record pumping the value of companies.

If he owned 0% of both companies as CEO he could still achieve both goals.

Recipe for not thinking anything is important: split your holdings into two investments.

Recipe for thinking two things are equally important. If one of those is as intrinsically unimportant as Twitter, the other is too.

Maybe he sees twitter as a threat to his other goals? 'Whitey on Mars' could be very compelling to the twitter crowd.

Like it or not, Twitter is extremely important. It sets discourse and gets politicians into office. Remember how much Trump's tweeting dominated the news cycle? Elon buying Twitter isn't him saying he thinks it should be important, just that it is.

So, this is his entree into politics? A way to drive money at federal-government scale the way he wants?

Possible.