Hard work alone can only take you to a certain level and that level is nowhere near no.5 in the world. Of course he's got talent. I hate the guy's tennis but claiming he doesn't have talent is preposterous.
That's just an assumption.
He's got qualities and some talent.
But we have to measure the talent among the top 100 players, Ferru would be in the 90-100. Qualities and work - N1.
If Federer has 100 units of talent, Ferrer would have 10. It's not like he doesn't have any, but it's far less than the usual for a top player.
Tsonga would have 90, Berdych 80 units, Tipsarevic 60, Nadal 60, Murray 80, Djokovic 80 as well, etc. Ferrer in my book has 10 units. No pro player has 0, that's clear.