PLA is easy to recycle, though as I said I mostly print PET. That does seem to be recyclable though I question the cost/benefit of doing so since the recycling itself has cost and it may weaken the plastic.

Personally I have a bucket filled with the scraps till I can figure out what I want to do. But I know I've thrown away far more plastic packaging than I waste printing so I don't stress about it.

Nevertheless your point is valid and needs to be considered as 3d printing becomes mainstream.