Series wouldn't have even made sense with Renton.
And seriously, the people who say things like "Dominic would be a better main character blah" aren't even thinking it through. Every episode would be:
Dominic: Anemone, I have done something that is in your best interest.
Anemone: *bash* or *snide comment* or *both*
Repeat until the very end.
But hey, I've gotten used to /a/ trolling good animes and good characters so I can't say it bothers me much anymore.