The thing about common carriers is that they're designed to be the carriers of last resort. They have special dispensation from a governing body to operate and -in return- they are obliged to offer their services to all who can afford them.
Common carriers are a long-standing practice that has clear benefits for society as a whole. What's more, back in the 1960s and 1970s we -as a nation- realized that there is value in helping the weak, infirm, disadvantaged, and those subject to discrimination participate as fully as they are able to in the public sphere.
If you want a somewhat less academic reason, remember that you can be afflicted by illness, infirmity, handicap, or -albeit on a longer timescale- discrimination at any time. When you're down, it's good to have services available that help prevent you from hitting rock bottom and allow you to help yourself get back on your feet quicker than you would on your own.
Common carriers are a long-standing practice that has clear benefits for society as a whole. What's more, back in the 1960s and 1970s we -as a nation- realized that there is value in helping the weak, infirm, disadvantaged, and those subject to discrimination participate as fully as they are able to in the public sphere.
If you want a somewhat less academic reason, remember that you can be afflicted by illness, infirmity, handicap, or -albeit on a longer timescale- discrimination at any time. When you're down, it's good to have services available that help prevent you from hitting rock bottom and allow you to help yourself get back on your feet quicker than you would on your own.