I literally just connected through SFO and wanted to buy a bottle of water to have on the long flight... I forgot to buy a bottle at my home airport. But I wandered up and down the intl terminal and didn't see any, so I did without. I went into one store that had every kind of sugar drink, but no water, which I just thought was weird, but now I get it.
Personally I don't have a problem with the fill stations I have used. I like to buy one bottle of water and refill it until it starts to get crunched up. I'm mostly concerned about the taste of the water and you can't be sure with the fill stations like you can with bottled water. Oh well, luckily I'm in Japan now where bottled water is legal...the bathroom fixtures work all work awesome too; as if they realized plumbing is a good thing and decided to keep doing it properly.