And frankly, the math isnt bad.
Looking at their cheapest plan which is $7 a month for 20 pages. 20 color prints from staples is $13.20. 20 black and white prints is only $4 so if you are never doing color it is questionable.
But the math gets better if you go slightly higher. 50 pages (2.5x the previous tier) is only $9 instead of 6. 50 color prints from staples is $33. 50 black and white prints from staples is $10.
And yes, I realize that if you were to buy the printer and buy the ink it would likely be cheaper. But first that requires being able to spend the money on a printer, which not everyone may have that money or it will have to go on a credit card.
Second you may have to worry about dry ink if you really print that infrequently (I honestly don't know how big of a problem this really is, but I know its a thing I see repeated a lot).
I am just saying, HP has some some shady stuff. I am not necessarily giving them a pass with this, but for infrequent (but consistent) printing it isnt horrible and you can do it at home instead of needing to go out.
Edit: However that privacy policy is horrible, and does really ruin a plan like this.