The petition’s is offering to bribe faithless electors (pay their fines). It’s not an offer to make the electors rich, but it’s still an offer of money in hope of influencing their votes (why else include it?) It says Clinton supporters would be “glad” to pay. That’s a smear on Clinton supporters.
Beyond that, it’s plainly unfair to rewrite the rules retroactively to get the result we want. Had popular vote been the goal, there’d be different campaigns, different turnout, and quite possibly different results. It’s like scoring a chess game by checkers’ rules, as someone put it.
When Trump does corrupt or unfair things, we’ll need moral standing to oppose him; so let’s not do such things ourselves.