There's definitely no ban for Russia! The server is in a datacenter in Japan and sometimes the routing from your ISP to the datacenter can be broken or extra slow (this is true when reaching any server). You could run a trace route to see where it fails:
Windows
1) Click Start (Windows 8+ users start on step 2).
2) In the search field, type cmd.
3) Right-click on CMD.exe and select Run as Administrator.
4) Type the command tracert esotericsoftware.com and press Enter.
Mac
1) Go to /Applications/Utilities and start the Terminal application.
2) Type the command traceroute esotericsoftware.com and press Enter.
You could contact your ISP ask if they can improve the routing. Even if the failure is out of their control, they might be able to avoid the bad routing.
You can try accessing the Spine website through a server in Europe, which likely uses different routing:
Spine: 2D skeletal animation for games
We have external services monitoring the server
we'll get notified if it ever goes down and will get of bed to fix it if needed. The server is up and hasn't been down lately.
