Ripple enthusiasts are too smart for that, and Litecoin users are too stupid.
Don't forget that Litecoin is essentially a coin that's build to be easily mineable with botnets.
Yeah, what system does Slashdot use? Or CNN.com? (any major news website, most are immune to DDOS).
They aren't immune. They are just big and therefore expensive to attack.
Even banks can be attacked :
http://www.informationweek.com/security/attacks/bank-ddos-attacks-resume-wells-fargo-con/240151825The folks that attacked those banks weren't even all that powerful. Just one random group of angry hackers.
The problem is more systemic. For example, there are DDoS extortion cases where it's less costly for a victim site, like a profitable gambling one, to pay a ransom then suffer extended downtime.
MtGox is effectively a profitable gambling site.