Price, maybe? He had a 2TB Time Capsule; the same storage space on S3 would cost $265/month, excluding traffic (that's $.12 more per GB downloaded). Not to mention that restores would be much slower.

I don't know about you, but I know I'd rather use those $3200/year on other stuff and just get a decent NAS.

Crashplan and backblaze both offer unlimited storage for way cheaper (roughly $260 dollars a month cheaper). Don't get me wrong - I'm all for onsite backups, especially for speed of recovery, but there are realistic & affordable options for cloud-based storage.