It's because it is a partnership and everything is passed through to you (i.e. income in many different states). This is just me personally so maybe it's less for other people.
Well I hold ETE and I can tell you that I filed in 14 states last year. I would imagine that 10 or so were the result of ETE.
It's always been their style to not provide forward guidance, so that explains why you don't see any.