It's just not optimal and therefore you want to minimize it if you can't avoid it. Without coastal access, you can't build a lighthouse, which means those tiles are only producing one food and two commerce (three if you're financial) and can't be improved. This makes the tiles only marginally better than tundra. I can tolerate one tile like that, maybe two, but three or more and you start looking for a better spot.
This early in the game, the possibilities are wide open, so there's no reason to settle on (or for) a sub-optimal location. In addition, remember that this is your first city; it will be one of your largest. It's also the capital and will likely be the beneficiary of the bureaucracy civic, so you want it to be the best it can be.