Major weather patterns move W to E in North America.
Local wind conditions are affected by winds below the jet stream, terrain and daytime heating and may be far less predictable of direction and intensity for days at a time.
The Race Across America has always been held W-E for good reason(s).

That being said a tour is not a race and if one spends all of the $$$ and effort to arrive on the E coast with a properly equipped machine and the time to ride back to the W coast: Why Not?

-Bandera