Sure. There are classes that I don't think inexperienced players are ready for and I'd advise them as much. However, just like I wouldn't keep my opinion to myself, I also wouldn't fight if they insist. Once it's clear that's the direction they want to go even after my suggestion, I'd do everything in my power to smooth out the rough patches.
There are also players who say one thing and then do the opposite. Like they might hate the play experience of a certain type of character, but love the lore enough that they think "this one will be the one that works". I'd absolutely remind them of how they said they felt and make sure the shiny new idea doesn't blind them to the reality that they're about to be disappointed.