In my experience, it would generally refer to incidents which have happened over a long period. As a decision or proposal, it may well have been prompted by a very recent incident. That is, there may have been a long series of incidents leading up to this statement, and the decision/proposal at the time of the statement is to lump them all together and forget about them -- write them all off.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.