Why is it "your" growth and not "our" growth? As a matter of public policy we seem to have decided that "we" "need" to have growth, so I don't see why you feel that you're off the hook in this.
Good question. First off I personally don't subscribe to the growth model, but yes I agree it seems to be the public policy foisted upon us by the power brokers. Second, we can have growth as a country by building
new communities and not diluting existing communities. When we want to
extend existing communities, that extension has to pay its own way. This is not the same as an existing community deciding they want to have more local services, say a theatre or arena, then the exiting members should pay for that. The community has built the infrastructure, and should benefit from it. That has nothing to do with personal mobility, you are welcome to join the community by buying a house from an existing family that has supported it and the house price will reflect that level of service.
Now we come to developers. They see two communities (different sides of the track so to speak). They decide to build in the one that has the better services, because they know they will be able to sell the house for a higher price. They are the ones that should be paying extend the community, not those who built it in the first place.