To be fair, 10 men's teams is only 1 fewer than four years ago (to keep with the Olympic cycle in terms of comparison), and that still included Russia. Another four years back, there were also only 11 teams, and that included both Russia and Belarus. Four years back again, there were a bit more, with 14 men's teams, but only 9 women's teams (including Russia and Belarus).
All in all, at least as far as the past 10-14 years or so are concerned, the numbers aren't really going down that much if you don't count the two now banned countries.
I do agree that in general it's a shame to have so few, but I also think it's understandable given that short track speed skating is quite a niche sport.