It’s not about doing more than one thing at once, it’s about picking your battles. Leaders have a limited amount of what I call “credibility capital” (see https://jasonlefkowitz.net/2003/03/where_leaders_f_1/) they can use to get things done. The more of it you spend on issues unrelated to your core strategic concerns, the less you have available to spend on those.

Some leaders have tons of credibility capital banked away, so they can afford to freelance on the side. But freelancing is a luxury. Spend too much on that and you’ll fail at your main job.

It's not really about leaders at all but about the public and press who will listen to and amplify anything leaders say even if it's off-topic bullshit.

>You should be able to do more than one thing at once.

Depends on the things.

Remain President and play golf? Sure.

Remain a spokesman for free software and repeatedly and publicly expound on your belief that pedophilia isn't harmful, and that children are capable of sexual consent? Yes, apparently.

That, and then toss a match on the PR tinderbox that is MIT's involvement with Jeffrey Epstein with a tediously legalistic argument over the definition of sexual assault which appears to the rest of the world to be an attempt to defend Marvin Minsky's alleged involvement in child sex trafficking? No. Turns out that's the straw that breaks the camel's back.