Other than that, there are bad points about them both.
With Le Pen it is undoubtedly the very ugly undercurrent of racism and anti-semitism. Yet with Melenchon, the problem is economic stupidity of a Venezuelan level of ghastliness.
A 100 per cent tax rate gains no revenue whatsoever, but that is proposed. In an ageing country, he proposes lowering the pensions age. He would kill off the nuclear industry which supplies 75 per cent of current electricity, and in general appears about as well informed as Chavez himself.
Not an appealing choice, but as your parents should have, but probably didn’t, tell you about choosing a mate: ugly beats stupid every time.