if nodes (wholesale) can't withstand a DDOS attack, bitcoin isn't very robust, is it? indeed, there are various optimizations that could and should be implemented to assist in withstanding DDOS. feel free to contribute code to assist.
if nodes can be DDOSed to the extent that overall node health (and decentralization) are threatened, that has fuck-all to do with "centralization of development." it simply means improvements to the protocol need be made.
Tell it to my neighbors. Their Internet service was taken down for several hours. The criminals DDoS'd the entire ISP, not just my node. If my node had been DDoS'd that would have been an annoyance, but I would not have called it a terrorist attack if there had been no collateral damage.
I have talked to customers of my ISP who experienced the Internet outage. They know nothing about Bitcoin and are not interested in it. Their experience was collateral damage. Not just Internet service but also telephone service was disrupted because of this criminal attack. People could conceivably have died. Wake up. Grow up.
This is why we want Bitcoin nodes running in as many ISPs as humanly possible. Ideally on every ISP (although one wouldn't make it such a hard requirement that the system is unpractical).
In the end in a system with so many different constraints and where some of them are hard to measure or even agree to a target on, judgement calls need to be made.