Is it just me,or do others find it really difficult to thin out seedlings?

I seem to have a surplus of onions, cabbages, cauli's, leeks and lettuce.

I'm getting a bit short of space and pots for potting on, so I am forced to throw the thinned out seedlings away. Even though it means the remaining ones will do better, I find it just so hard to waste all that potential

I didn't expect such good germination rates - note to self for next year - sow much thinner.