I haven't used Scout but I have the same problems with that as I do with NewRelic. Their plugins is built for their vendor agent. With that said I do like the opensource plugins of Scout.
The issue is that we are now a lot of people that tries to solve the same kind of problems. Everyone seems to be writing collectors that reports information to backends.
They all implement some kind of RRD or Graphite service hooks. It would be nice if all I should do to upgrade was to point my existing collectd collectors to NewRelic or Scout and be good to go.
Instead, I now have to reconfigure my whole stack, install their agent, add their plugins for my software, make sure things are working and then switch.
I am not advocating that everyone should use Graphite, I am just advocating that we should have some consistency between these systems, so we can use the same collectors no matter what the backend is.
I had a feeling that Graphite+Statsd was where the community was heading given that both Etsy and Github are using that.