Why not? Nothing you wrote suggests that we cannot have both. In fact, Musk bought Tesla, is not an engineer, has no engineering training or education or engineering accomplishments (the code he was writing for the company that became PayPal was notoriously terrible and had to be scrapped). Say what you want about Zuck, but if you plopped him down at a terminal and made him do the job of one of his own senior Devs I bet he would be able to do it. Musk couldn't do the same for any one of his companies in any of the technical positions.

I find it interesting that someone states something like 'you can't it both ways' without thinking it through and while presenting no reasoning for it, and then just leave it there like it is now a rule we must accept.

You should probably fact check this statement. There are plenty of people on quora or even here who worked with Musk. You are completely wrong on this.