Yeah, software that's constantly monitoring for backup is going to have a cost in resources. Crashplan uses quite a bit of RAM as well (about 4 TB of crucial data on one of my file servers also goes into the cloud), which is why it's running on the server rather than my main rig.
Robust software requires resources to run. That's not saying Backblaze is perfect -- I don't personally use that -- but the video maker here doesn't really present much of an argument. For example, direct comparisons of resources for software doing identical tasks may have made the point. Mostly just seems like someone who got pissed off at Backblaze.