I don't think that's fair because when a player has won/played a big match, sometimes that's the only time someone has seen him play. Like, I saw Gulbis for the first time against Blake. I feared saying something good about his game and future because I'd be labeled a bandwagoner.
It's fair, like with Tsonga. He had been around for a while, then there was the massive explosion of fans, now he is injured, he is off the radar, then if he has another big performance then they will be back in full force.
Same with Gulbis he has been around since 2006.