A bad compromise is a compromise which nets both players a lesser sum of happiness than what a good compromise would, or no compromise would.
If you look at things in terms of sums then an event which works to my advantage and causes you distress will be what we call a 'zero sum game' since my benefit is equivalent to your loss.
Likewise, if the event makes us both happy then the sum is positive.
If an event makes me greatly happy but you slightly unhappy, then the sum is positive.
A bad compromise has a lesser sum than both of these. Bad compromises may fail to make either party happy or are compromises which are done because one party wants a solution which benefits himself more (at the greater expense of you)
An example of someone who may enforce bad compromises
This is not my result, its just something I pulled up in a google search.