They didnt though. They answered why Tony would go to Peter, but not why he wouldnt approach any of the adult heroes there. The writer provides some of his own theories after which I guess could make sense for Daredevil, but Skye? That theory doesnt apply to her. Is it a big deal? No, but stuff like this is going to become more glaring as things start to expand.
There is absolutely no reason why Tony should've considered any of the currently known adult heroes. Everyone on AoS is undercover and therefore unknown to him. Or, if they are known to him, it's likely because he's seen their faces on wanted posters. And the only Netflix characters we have so far are:
Daredevil - who, seen from an outsider's view, is just a tenacious guy in a mask who probably doesn't have the abilities necessary to keep up with the Avengers. He is also tainted by accusations of criminal activity.
Jessica Jones - whose abilities may or may not actually be known, but who definitely and obviously doesn't have the temperament to be an Avenger, and almost certainly would refuse if asked. And she is also tainted by accusations of criminal activity.
Luke Cage - whose existence is still secret. And even if Tony knew about him, he literally got his powers from a prison experiment, so he also does not exactly look like prime recruitment material, either.
Elektra - who is also a secret, and kind of a psychopath.
Stick - who is also a secret, and kind of a psychopath, too.
Punisher - a complete and total psychopath.
The only other legitimate option he could've had would've been to recruit a different hero that hasn't been introduced yet or to contact Thor and ask for help, either from Thor himself or his asgardian friends. And Thor probably isn't picking up the phone right now.
