He's a .251 lifetime hitter.
Maybe he needs more time and he just never figured it out
Right. So you must be thinking about the part of the conversation where Robbie Grossman said, "Blessedly, I've been such a valuable player throughout my career - never in the position of scrapping for a roster spot - that managers have uncritically agreed with my view of spring readiness and just stopped putting me in the lineup after ten at bats."
Because that's the only way I can imagine you're still comfortable making this uncharitable connection between an in-game interview and his work ethic. But the good news is that the conversation you seem to have heard never happened, and since 2012, Grossman has logged 18, 22, 50, 53, 39, 42, and now 14 (that's four more than ten, if you're scoring at home) at bats in Spring Training games.
The silly thing about all this is that I don't carry any water for Grossman the player. He's an okay bench piece, but doesn't do enough good things well to ever have the liberty of going into spring without working his ass off to win a roster spot. But I think pretending we know the slightest thing about his work ethic from this interview is contemptible. Like, it's for villains. Just don't do it.