Given that all of the previous military coups in Turkey were carried out by the secularist military establishment, you need to present evidence beyond accusations that the Gulenist movement, an Islamist movement, is behind this one. Show us the quacking and walking.
For walking, multiple sources confirms that for years, they stole questions for army and police college entrance exams.
Of course also the statements of coup officials.
The quotation you point to has nothing to do with the coup at all, it's from the 90s and describes a totally different hypothetical situation, one in which his supporters have seized control of all state institutions. That is clearly not the case. It's Erdogan's AKP that has gradually seized control of all institutions in Turkey.
One or two weeks before the coup, some army officials in Izmir were detained linked with a previous army spy case and they were linked to Gulen. The supreme military council was about to be happening with the agenda of sacking multiple army officials related with him.
IMO, coup was not solely planned by Gulen, but they were involved significantly.
Lastly, again, check multiple coup officials' statements.
The 2013-2014 protests consisted of just about everyone who opposed Erdogan.
https://en.wikipedia.org/wiki/2013_corruption_scandal_in_Tur...