Of course I am not arguing that there is some sort of sub-standard gene pool. I am saying that the system is not producing enough top level talent to win international tournaments, and that in fact the actual numbers of quality players is falling off (declining, reducing). The expected increase in talent from the creation of the KHL and MHL, which was reasonable to expect, has not materialized. The talented players who do exist are mainly in the NHL (and for youth, CHL), and they seem to be showing a diminished interest in coming back to Europe and engaging in an exhausting tournament in the WC.
Thus the convergence of all of the mass injuries afflicting NHL players at the end of the season. Tarasenko did in fact have surgery, which means that he needed surgery in the SC playoffs but put it off to compete for St. Louis. I haven't heard about surgery for anyone else, which means they just wanted a "rest." They had 12 to 14 days to rest before joining the national team, so I interpret as largely being disinterested in going through everything involved to join the team. Even Svechnikov's CHL management offered a confusing reason for why he was unable to join the U18 team. In any case, the lineup for 2018 suggests that there is a kind of black hole of talent available for the team.