The way i see it is there has to be some sort of major sacrifice that has to take place in order for rick and the gang to be super angry with him lying about having a way to fix all this.

After all currently there isnt any real downside to them having to go to DC other than the potential dangers along the way (but the world is a dangerous place right now so thats kinda moot), there isnt an opportunity that they would be wasting, or a characters life that wouldnt have been lost by going to DC.

What else do they have going for them currently? the prison is gone, terminus was a lie there really isnt a downside in trying to go to DC