You're missing the point. Birthright citizens have nothing but "geographic location of birth" to qualify them as citizens of their country. They literally (in the real meaning of 'literally') did nothing to become citizens. Their children will also likely have to do nothing to become citizens, as long as they're born within the same borders. What motivation do people who expended zero effort to become citizens currently have to help or vote to make immigration rules more sane?

Just fyi: most countries do not operate a jus soli-based citizenship system. Probably because of the reasons you outline.

The government is supposed to represent its citizens, so, uh, no.

This is sarcasm, right?

If it didn't what would the meaning of citizenship be?

I suspect the post you replied to was sarcasm.

Indeed. Sarcasm is still as hard as ever to detect in the web.