I agree and wish Epson and Canon had an option to put down what's enough to ensure proper maintenance during periods of inactivity. If they could help us protect ourselves from under-usage it would be a big help! And you would think they would know how best to go about this, and welcome the extra ink usage.
I think they much prefer selling new machines, in Epson's case, and new print heads, in Canon's case. I leave my Canon iPF6100 on all the time, and assume that when I hear it agitate the inks and such that it also spits out a bit of ink. But I found out that if not used in over 3 days, it does a clean cycle. In my Epson days, the clean cycle used up 10ml of ink. Not sure how much the Canon uses since it doesn't report total ink usage like the Epson did, but if it is 10ml of ink then this is far too much when all you wanna do is print a couple of images that would use only 5ml of ink. So I've gotten into the habit of making sure to either print every 3 days, or do a nozzle check. This simple procedure has worked well as I have zero clogs, and also it never wants to do a clean cycle before a print.