When you start, features of the game get unlocked at each level. I loved that and couldn't wait to see what was next when I got to level 4, 5 or 6. Obviously that can't continue, but player ships do require you to have a certain level so there is still a strong incentive. For example when I achieved level 35 I became eligible for Mizar class ships, once I reach that system.
With my slow but steady style, going up a level doesn't matter much to me. By the time I've reached a system and earned the crystals, I'm easily at the minimum level for a ship. I'm not suggesting the minimum levels be raised as I am not a typical player. It might be nice to have some other reward or incentive for level increase but that might straight jacket people into a style of play or rate of progression that didn't suit them.