I use paper plates to re-heat things in the microwave -- sometimes as a lid over a bowl when I'm heating something that will splatter. I'll also sometimes use them to eat from, if I'm having a burger or sandwich. I don't use a lot of them, because they can be a waste of money, and they are no good for something like steak -- they aren't sturdy enough.
Now, on a related product, I use very few paper towels. I have a large supply of terry and microfiber towels I get cheap from the automotive section at COSTCO, and wash them to reuse over-and-over. Here again, it is a money saver. Plus, they work much better for cleanups than paper towels.
As for environmental concerns, I live in Texas, and folks here are proud of their "carbon footprints" and pass laws and do things just to piss off the "tree-huggers." For me, conservation is more about saving MY money. If it helps the planet, that is a coincidental bonus.
CD