If you're going to have a national championship, there is going to be travel. If you break it down into conference championships, feeding into regional championships feeding into national championships, you might limit travel for weaker teams, and increase travel for nationally competitive ones. There will always be someone that won't like it.
The other approach is to just stop at regional championships. High school stops at states because they run out of time, and nobody would pay for much more than that. That's not a "national" league.
It just depends on what you want, there are formats out there to give you whatever level of travel you desire. ECNL tailors its product for its own purpose, as do all leagues.