There's only one little problem with that: It's forbidden in Minneapolis to refuse to convey a passenger in a taxi cab.
341.170. Duty to accept passengers.
No driver shall refuse or neglect to convey any orderly person or persons upon request anywhere in the city unless previously engaged, provided that such person agrees to pay the legal rate of fare. No taxicab driver shall refuse or fail to provide services to any person protected under the Minneapolis Code of Ordinances section 139.10. No taxicab driver shall carry any other passenger than the person first employing the taxicab, except as provided in section 341.730, and then only with the consent of the first passenger or passengers. (88-Or-004, § 5, 1-15
Minneapolis Municipal Code
Title 13; Chapter 341; Article 1A
The only reason they could legally refuse to carry the alcohol carrying passengers is if the passenger refused to pay the fare or the cabby already had a passenger. The airport is trying to sanction the cab drivers actions by offering the cab drivers a way to signify they won't carry alcohol bearing passengers via a special light on the cab roof. How are the airport workers going to direct people to the correct cabs? They are going to have to interrogate them about what they are carrying no? Therefore to not "offend" a cab driver who is in violation of the law, the onus of burden is put onto the passenger. That's just not right.
I have no problem with the cab drivers religious beliefs at all. If they don't want to carry alcohol, fine. But when they take the job of a cab driver then they are beholden to the laws and regulations the cover their job. If they violate the rules or so devoutly disagree with the rules, then they shouldn't be cab drivers.
Condoning the actions of the drivers in this case is wrong since under the secular municipal code of Minneapolis the drivers are in violation. Period. Where does it stop? Will they soon refuse to carry women who aren't wearing the hijab? What special colored light would they get on the top of the cab for that? What if there was another group of cab drivers whose religious beliefs forbade them from carrying anyone who was not caucasian? Or what if their religion forbode adherents from carrying anyone who wasn't of their religious order? Would everyone have to wear little pins or badges identifying their religious beliefs so as to be instantly identifiable?
Are some of these scenarios far fetched? Prior to this cab incident I would have said yes, but when you begin to bend the rules for one religion or religious edict you eventually have to bend it for all and that's not the point of the United States. We are a secular nation of law under the guiding beacon that is the Constitution which while respecting the religious beliefs of citizens, trumps all other law espoused by religion, be it shari'a, Torah, or Bible.