what makes it a bad thing if entry level jobs have a little higher wage?

The cost of everything else will go up, wiping out any benefit from a slightly higher wage for the entry level employee but harming everyone else slightly. Multiply that by a few million jobs and you have an issue on your hands.

Let it happen naturally and the system will balance itself out. Force it and you'll destroy local job markets for those entry level positions. Force it nationwide and you'll screw over the entire job market.