One common (if vague) argument against upzoning and infill development is that infrastructure in place X (wherever the proposed development is) will somehow be overwhelmed by more important. When I see this argument I want to ask:
1. What infastructure are you talking about?
2. How is it currently inadequate in place X?
3. If you don't want more people to live and work in place X where do you want them to live and work instead?