Pruning != Scalability
Sure, you can chop a hole in the bottom of the bucket to dump some water, but it can still only fill up as fast as your tap.
Pruning allows you to manage the size of the block chain over time, not how many transactions it can process per second.
Although this is correct I still think that a scalable coin should also have pruning.
If the blockchain gets to large more and more nodes cannot afford anymore to save the whole blockchain.
This not only leads to centralization but the network would finally also get very slow or even crash as millions of clients cold try to request or send data to very few remaining full nodes at the same time that cannot handle that load anymore.