Hmm... Serializable isolation and concurrency go together fine and certainly don't require blocking or even locking when using MVCC and optimistic concurrency. For that matter serializable transactions and scalability are not incompatible either (though few NoSQL systems have tackled the problem yet).
I think the author's main point is that sub-serializable isolation levels are confusing and can lead to wrong behavior in subtle ways. I agree, but to me it sounds like the failing is in using too weak a consistency/isolation model, not too strong a one!
I think the author's main point is that sub-serializable isolation levels are confusing and can lead to wrong behavior in subtle ways. I agree, but to me it sounds like the failing is in using too weak a consistency/isolation model, not too strong a one!