Not that I'm calling you a liar (really, I'm not), but where on DGCR have people been saying that throwing flex shots will hurt your game? I've seen the "putter from the tee" meme (which is an extension of the Disc Down Agenda), but I haven't heard the flex shot accusation.
Are you referring to the idea of needing to throw a hard anny flex when the disc is too fast for you in order to get a usable flight? I could see how that could breed OAT, but all I have seen here is encouragement to learn specific throws (flex, hyzer-flip, tommy, etc) that will enhance your game and give you more/better options.
Maybe I'm spending too much time in the landfill/water cooler.... :\