Almost immediately, several thousand were conveniently rounded up.
The soldiers deployed to the street didn't know whose side they were on.
Jets were flying low overhead (were never on the side of the coup, but it made them think they were)
Social media was blocked (on who's authority?)
There was no attempt to kill or arrest the leaders of the regime (sort of #1 thing in a coup)
The hotel Erdogan was staying in was "attacked" after he left, which is very convenient and gives him martyr cred without doing anything.
The "coup" thought they had widespread support but they didn't.
Erdogan made them think the air force and other army divisions were with them, when even the soldiers deployed didn't know what side they were to be on. They had no orders to actually do anything coup-like)
I think this was all a psy-op orchestrated by Erdogan who knew that a handful of Generals opposed him, so he encouraged them along and got the others in the military to play along too.
A Governor, Generals, 36% of the nations judges, at least 5 bus loads of Military High School students and others were rounded up quickly. Sounds like they already planned who to purge long before the "coup".