I'd beware conflating "interpersonal skills" with "playing politics." For CEO at least (and probably CTO as well), there are other important factors in job performance than raw engineering talent. The subtext of your comment is that the companies you mention were somehow duped into promoting these bad engineers to executive roles, but they might have just decided that their CEO/CTO needed to be good at managing or recruiting or negotiating, and the star engineer team lead didn't have those skills.

Second, I think that the "playing politics" part is true at some organizations but not at others. Perhaps this is an instance of All Debates are Bravery Debates.

My model is something like: having passable interpersonal/communication skills is pretty much a no-brainer, but beyond that there are firms where it just doesn't make that much of a difference, because they're sufficiently good at figuring out who actually deserves credit for what that they can select harder for engineering ability than for politics. However, there are other organizations where this is definitely not the case.