It's been an eye opener for me how little people are willing to take on-board in a tutorial level (this is a general observation not directed at any one individual), even if you explain a feature, unless it's pointed out in the simplest, most direct fashion. Think this is due to the large amount of product out there to try (so many demos, so little time), that people have a low threshold for any obscurity.
I don't really know, some people just enjoy exploration and experience more than others, some people just want to 'play the damn game'. I dunno, I didn't have any problems with them. Turrets are turrets, they are a problem for the player to figure out, having to tell them that it will hurt you is like telling you hot coffee is really hot in big red letters. :)