Screw it, I'll host it myself
markozivanovic.com
markozivanovic.com
For many (most?) people this is too much; enough for them to give away some control to a third party - and get a similar product for free.
Even if you have to trust a 3rd party with your data, (1) you can minimize the privacy risk with encryption and (2) usually VPS/cloud providers have different privacy guaranties than free Google drive...
If the concern is: my apartment burned down and I need a backup from this past month, it should be ok (given the double copies & other redundancy)
If the idea is that they feel safe deleting things from main storage because it's backed up several times, your concern is probably right. I'm not sure tape is really justified for their use though. (What else has comparable longevity?)
And of course you could back up somewhere else. But eg mongo doesn't let you delete from their cold storage iirc (I can't validate this claim! So consider it hearsay)