It's offensive behavior, to be certain. But unless it's legislated otherwise, it's "okay", yes.

For the record, I'm 6'3" with rheumatoid arthritis, and I despise flying in coach. But I have to separate the irrationally perceived personal affront by the airlines from the reality of the situation: I am flying by choice. If I had a specific accessibility concern (and not a convenience or comfort one) the airline would accommodate me.

>"I see this argument a lot of time but I still don't really know how exactly that redeems companies bad business practices and user hostility."

It's not supposed to redeem them, that's where you took a wrong turn.

>"What is the purpose of this argument? Saying that it's ok? If not, what else?"

I believe the purpose is to tell people to "relax, it'll solve itself", or perhaps: "relax, if there was no coercion, then this is precisely what the market wants, or is willing to bear"

> Also, what is the alternative? Use a cargo ship over seas? Choose from another 5 companies with same crappy business practices?

It depends on where you're going. If it's an overseas trip, you could video conference or telecommute. If it's not, you could drive yourself or take a bus.

Or a train.

In the US? Hah. I once looked up the time it would take to take a train from Seattle to Chicago. Three days, one way. I would have to spend a week vacation just traveling to and from my destination. The flight between those two cities is four hours. Trains in the US are substitutes for driving, not flying.

There are other countries.