You can clone with
HTTPS or Subversion.
Remove .DS_Store from .gitignore
This should be in a (Mac) user's ~/.gitignore_global
While I agree it would be ideal for a Mac user to handle that locally, the reality is very few actually do. Why take the risk?
It's a relatively minor risk and we can address it on a per-pull-request basis. I believe it's worth taking the time to explain the best solution when people make this mistake.