Why is their international hockey team so terrible? Ukraine has a much larger population than the European powerhouses of Finland/Sweden/Czech Republic/Slovakia so the larger talent pool should compensate for the relative dearth of resources. Is it a matter of most upper echelon players migrating to Russia, an issue with coaching, or something else altogether?
Ukraine is located on roughly the same latitude as France, it's not a natural winter sports country like Canada, Russia, Sweden and Finland; the Czech Republic is a bit of an outlier in hockey with a strong skating tradition and Slovakia isn't exactly a "powerhouse" anymore.
The number of registered hockey players per 1.000 inhabitants in Ukraine is on the level of Poland, Romania, Bulgaria, Serbia, Bosnia, Turkey, Greece, Spain and Portugal (0.01 to 0.1), below France, Italy, Germany, UK, Belarus and Lithuania (0.1 to 0.5). Russia is in the 0.5-1.0 tier (far higher in the north than the south obviously). Norway and Iceland make up the 1-5 tier. Slovakia, Switzerland, Austria, Latvia, Estonia and Sweden are in the in 5-10 tier, while the Czech Republic and Finland are the only European countries in the 10+ tier. Apart from a band of Central European winter sports countries the most important factor is how far north the country is located and Ukraine is a "southern" country. It's like asking why Alabama and Georgia aren't as good at ice hockey as Minnesota and Michigan.