Porte doesnt have any mental problem. He was in shape to win the Giro, just bad luck put him apart, he was saving energy and at the same time climbing like Contador. We dont know how he would have finished il Giro, if he fade at the end, but we just dont know, so, the rest is speculation, becouse he has been always a domestique in the GT.
He did well to leave il Giro, I dont undertand why Urán followed quite ill and with crashes if he had to race le Tour as well. it is stupid, although he got some good results at the end. That is not mental weak, just is to be clever.
I hope he recover soon his heath problems (we are a lot of people with the same problem un february) to see his level this year, but he showed already in Australia his strenght, climbing Willunga at the same time than last year, the record of the climb.