> Get rid of all texture, and you might end up with cold, sterile designs that scare users away.
I'm on board with the usability argument, but I don't think that removing gradients and drop shadows necessarily results in designs that "scare users away." If anything, I think that abandoning realism allows you more freedom in making a warm & inviting designs (e.g. some downright unnatural combinations of pastels that would look too busy with those touches of realism).