Plenticide is the deliberate 'pruning back' of 'excessive' anything (and everything) - simply because some/many/all people feel totally overwhelmed by abundance, either some of the time or all of the time.
Abundance of choice, abundance of complexity, abundance of competitors, abundance of debate and of decisions, the list goes on ---- plenticide happens because of primal fear from one or all of these reasons.
It needn't involve killing humans or even living beings - killing ideas and choices will do just as well in providing these plenticiders with their sought for relief.