I've gotta agree with the author. I'll never eat farmed salmon again. I've had it a few times and would rather eat tofu than farmed salmon (of course, I'd MUCH rather eat the coho I catch myself). While I'm definitely not a vegetarian, I have to agree that it doesn't make a lot of sense to turn several pounds of fish meal into one pound of farmed fish that doesn't taste so good. Ditto for turning pounds of edible crops into many fewer pounds of pork, chicken or beef.
As part of my healthy diet changes, this year I started eating a lot more fruits and vegetables and a lot less meat. I still LOVE meat and fish and don't intend to go all vegan, but I think it's a good idea for both health and environmental reasons to limit the intake of all farmed meats and fish.