Personally I have no problem with people praying but I don't want to see it or listen to it or hear about it. Just go in the closet and close the door. Knock yourself out.
Actually, we're supposed to pray in private.
Matthew 6:6 New International Version (NIV)
6 But when you pray, go into your room, close the door and pray to your Father, who is unseen. Then your Father, who sees what is done in secret, will reward you.
Of course that is so to avoid the appearance that you're doing it to boast or call attention to yourself. Other than that...I don't mean to offend but I can't help what other people do in public and if me and my wife's prayer before we eat at the restaurant offends you, do what I do and ignore the offenders. We'll all get along just fine if we learn to ignore rather than complain.