The problem of DDoS in high tier gaming isn't a new one, probably 10 years or longer. What I don't understand however, is why these players who are affected by DDoS are still leaking their IP with Skype all the time.
Uninstall Skype, get a new IP, and it'll probably never happen to them again.
Or use a secret skype if it is necessary... A lot of streamers use skype to provide content of them interacting with others in an interesting way (and skype is pretty good for this without the hassle of ventrilo, mumble, teamspeak, or whatever alternative).
I don't see why more of them don't make token skype accounts regularly. It isn't much of a hassle and it raises the security bar quite a lot compared to always using the same account.
Uninstall Skype, get a new IP, and it'll probably never happen to them again.