I like the "It's hard to beat closures for elegance" argument, but I haven't really tried the arc way for web apps yet. It's also true that over time we see higher-level languages win out over their lower-level counterparts despite initial objections about performance. So it might be that closures win eventually over initial objections about scalability. But I like readable urls, http://example.com/a?fn=fkg34lk doesn't really tell me anything.