:shrug:
Yeah but just as people who dislike fast travel now got a valid alternative to get around fast in the world, you still got your valid alternative to use fast travel anywhere you want to; and you can still completely not choose to use carriages at all.
All you gotta do is not talk to the travel NPCs and you're fine...
Although I agree that if I were you, I would still also prefer not being able to travel at all to a city before visiting it first.
But it would be really illogical if you only use travel services as soon you visited the city by foot first. But despite this being illogical, I agree with you. They could have made so that you can't use travel services to a major city, but have to walk to it first. It would have been better. FORCING you to discover a major city by foot is an amazing experience to be honest.
If Bethesda doesn't change this, it's not the biggest deal in the world though. Since once you've discovered that city, you would be able to travel to it anyway. It's not a great loss, but it's still kind of a loss from my eyes as well, yeah.