I always have to laugh when people feel that a tank will make fish or shrimp happy because it's attractive to human eyes.
As for it being inhumane, that's a tough one. Many fish we keep actually live longer than they would in the wild but is that good? It' can be easy to justify a fish loss thinking, well, most fish bought in stores don't even last a few days so I do way better than most.
More importantly, you have to remember how most are collected from the wild and shipped. Most don't survive this. I think with many wild caught, freshwater fish, like 1 in 10 actually survive the trip.
Now that doesn't sound humane but what about what we eat, that seems way more inhumane and I am not going to go vegan myself. But, I also don't live somewhere where I could raise my own food, really kill my own food on a regular basis so that won't work either.
Every time I have a big mishap, I do stop keeping fish for awhile myself, unless enough survive that need to be in a school.