The Sora thumb shifters cannot be reached in the drops. That's why people moan and B**** about them.

That said, it's trivially easy to shift your hand to the tops, even if you're in a hard sprint and need to actually use that button - I've done it many times, and don't understand what all the fuss is about. I'm actually much more convinced it's because people are more than happy to justify their higher-end (105-DA) shifter purchases - when in reality, I'd bet that if Sora was the actual top of the line, people would be raving about how solid it was. Really, I've had no problems whatsoever with the shifters, even with fast competitive riding. You'd imagine that anyone who develops bike handling skills would find it trivially easy to rotate that hand to the top to push that button - it was never remotely hard, ever.