MF has a support

One of the biggest strengths MF has is that she's a duo laner.

If her support is Braum, Blitzcrank, Nautilus, Thresh, Morgana, or Lux, the alternative to an easy double-tap is an easy skillshot. The fact she punishes hiding behind minions while hiding behind minions is the only counter to her support's main ability is the issue, not the damage it deals when she's alone.

The removal of the additional damage it deals after killing a minion is justified based on this and not how the ability is used when she's completely alone.