Nobody is seriously saying, "let's change the rules now so Hillary wins!" Some people are calling for electors to not vote for Trump, but at least that's part of the original intent for the electoral college (and it's not likely to happen anyways).
But lots of people are saying, "This system is obviously broken since the will of the majority was not enacted, let's fix it."
So nice strawman, but I think I just burnt it down.
In this case, it would be like the soccer team picking a really bad goalie, so they want to change the rules so goalies have less effect on game outcome.
If the DNC were correct about their assumptions, they should have won by a landslide. This should not be about changing the rules, it should be reevaluation of our beliefs and course corrections.
If the rules are bad, change them the next time around.