I buy fish i will have to upgrade for whats wrong with that!?
I fail to see your argument. The fish dont get attached to me, it bothers them not one bit if they move to a different tank.
I have my tanks as a hobby, they are decoration, fun to watch and care for. I like my fish, but dont grow attached to them like i do my dog for instance. Its not because they are any less of an animal, they are just a different kind.
For me, i really care about my cars, I was really upset when someone crashed into (and wrote off) my pride and joy. I spent thousands of pounds on a rare car, had it all prepared and modified to my own specification. Some people think its silly getting attached to cars.
I just cant "love" my fish, i can appreciate their beauty, and will care for them as any living being deserves, but dont ask me to love them!
I will upgrade my tanks for the fish that require it, so whats the problem? A lot of people for instance (myself included) want to be able to have Oscars. Now i can house them fine at their current size, and was confident setting up a tank of that size. However when they get too large i will be returning one, and setting up a larger tank. This makes perfect sense as i feel eash time i run a slightly bigger tank i better understand the next larger tank.