Sorry, but I disagree with the keeping of fishes this way on several grounds.
first you say this:
1st, different country got different type of lifestyle.
doesn't float my boat at all. "culture differences" are no excuse for improper fishkeeping, or improper keeping of animals of any kind.
in china for example they wedge fully grown bears in little mesh cases, put a hole in their belly and drain off the gall.
might be "Chinese medication" but it's cruelty to animals of the worst kind.
in any book. there's too much "hiding behind cultural alibi" around all over the globe, here too.
but i won't fall for it.
second:
2nd, if that is consider cruelty than dun keep fish go around the whole world LFS...
be an officer because where they sell most of them in small little tank.
fish kept in a LFS are kept in transition; they come and go.
keeping the fish in the same way as they are generally kept at wholesalers or LFS is not done.
a fishtank should be an attempt to give the fish OPTIMUM parameters, not minimum!
third:
For me I WISH to get a mega tank for my catfish with strong system and sand too just like in the nature.
But...$$..space...family complain(I dun own the whole house) so at the moment it is rubber tank for me.
then you should refrain from buying fish AT ALL.
if you can't afford to buy a tank, why buy the fish?
ever heard of responsibility for one's own actions and of responsibility for one's own pets?
should have left the fishes in the LFS in the store until you could house them properly, but you didn't.
that's irresponsible behaviour and there's simply no excuse for that anywhere.
it's like buying a huge dog when all you have is a 1 room appartment. or making five kids but lacking the income to raise them in a home.
you just wanted those fishes without giving thought to keep them in a good way, in a well set-up tank.
no, you're definitely not making it any better with "excuses" like this.
I see someone who's into shopping spree, but lacks the discipline to keep thje wallet shut and pass on a fish he can't keep.
not good.
and please.....dfon't "hide" behind so called "culture", because then you diminish the ones in those countries who DO know how to keep fish as it should be done, and I dare say there are plenty fishkeepers in Asia who do run proper fishtanks. don't hide your own shortcomings behind others.
Perhaps before you make any remark,
there is some important fact that you need to know.
and perhaps you should think before you open your wallet and buy.
here's an important thing YOU should know:
anyone, even the most incompetant ignorant or careless person can buy live fish.
unfortunately not everyone can or will house the same fish adequately.
I rest my case.
The MTS continue to thrive. I have the use of a pteradoras granulosus if i want but i don't think he'd like the tanganyikan conditions 
that's definately worth a try
