Right on. I use Lyft and frequently leave tips when I feel the driver and my ride experience has been great. I also think the tipping experience is much more friendly to both the driver and the passenger (compared to say, a usual taxi ride) and I've rarely, if ever, had an unpleasant experience with Lyft.
I used to rarely use Uber (more outside bay area) though I did have Uber installed on my phone. But I uninstalled Uber a few weeks ago as I was feeling more and more uncomfortable with Uber's corporate behavior and their CEO's personal and political reputation. This was even before the latest spate of allegations of sexual harassment and other bad publicity. I don't think I'll ever install Uber app again... the tipping policy being just one of the many reasons for that decision.