There will always be both congestion and attacks against nodes: it's an open network where you pay for what you use. Classic doesn't solve either problem, because those problems will never be solved using the Satoshi design. (i.e. open network, pay for what you use)
You are changing the subject.
The issue is whether or not the Bitcoin community is going to stand by and allow a small, currently anonymous organization or special interest group to subvert its interests.
If so, then say goodbye to Bitcoin and hello to JPMCoin, or GovCoin, or SIGCoin. Whoever has the money to pay for the most DDoS attacks and the most shills will either get their way, or they will attack the network so that no one else can use it.
Allowing the current attack against Bitcoin Classic to continue unanswered is setting a precedent. If it is allowed to stand, it will be harmful to the interests of most people in the Bitcoin community by paving the way special interests. Don't let special interest groups control Bitcoin in the same manner they control so many other pillars of our civilization.