If you don't own the land and can't demonstrate a direct, severe impact to you and yours from the actions of someone else, you shouldn't have a say.

"More traffic" is not sufficient. I can actually sort of believe shade from an apartment building could count, but the impression I get is that is rarely a good-faith argument (and in any case it should only severely affect a few people in any new development, so you could easily justify just compensating them in some way rather than outright blocking a development.

They should have exactly the same say as everybody else in that electorate who votes. They should not get an extra say.