You have a like from me for the time and effort you probably spent looking for all these times in this post..
Yep, that´s one of the main problems of our sport. Our only above level swimmer in the entire history was Martina Moravcová, and only thanks her studies in Dallas. Yes, she was exceptionally talented, but I don´t believe she would have achieved even a third of her successes if she had not gone overseas before.
The other main issue is the infrastructure. No money, No fun. I do not know if we have even a single 50m pool in the country, we for sure have only a limited couple of small pools in the biggest cities, I do believe more than half of our population do not even know how to swim (yeah I likely exaggerating here, but you got the point), so it is hard to think high in this sport in such conditions. However, it is not only in Swimming
I could write novels about the lack of money, state support consequently bad coaches, resulting in many young athletes losing motivations early and leaving sport etc..., but Anyway, generally, besides Hockey all our sports education and system is outdated and ineffective. When you look at it, the majority of our "above level" athletes in individual sports come more from the family system, so outside of the "national" system.