In my experience, most TTRPG characters are motivated primarily by personal gain. They aren't necessarily assholes, but the default character is definitely a pretty mercenary individual.
Anyway, I'd say it's fine. In fact, I'm not sure why it even needs to be brought up (unless the campaign has a specific concept that isn't in line with this), though I'd appreciate that they did so. I think it should be assumed that players will make characters with varying, sometimes clashing personalities. That's how tabletop roleplaying works, it's one of the big things that differentiates it from just playing vidya or a wargame.
Seriously what's the issue here?