Idiot usually means someone who doesn't know basic facts or has trouble anticipating consequences for their actions. But I think part of GPs comment was to note that the concept of idiot needs to be readdressed. For example, if your hypothetical person has a family network (just another tool; but a v. good one!) that helps them, then they choose to either stick with their family or try to strike out on their own. We're already discussing the situation where they have chosen to leverage their family network.

I have never, ever, once in my life ever heard anyone say "Isn't that person smart, they managed to get their dad to give them a job"

And maybe one could respect people who go their own way to get out of their family's shadow so they can be seen as making it on their own. But if that's not the game then both people are 'idiots' (in this thought experiment).

Success is not guaranteed just because someone was sent to an Ivy League school by his rich parents.

This is the blank slate fallacy where people believe (for political correctness reasons) that any kid had same chance of success if he was given the same opportunity as the success of kids.