I think the key word is "should", at the end of the day everyone will keep their horses in slightly different ways and 99% of the time this is worked around what suits horse and owner. As others have said, it really isn't any business of anyone elses' how you work your horse.
In a way, it's the same mindset that gives rise to both the "you should be riding your horse by now" and the "you should give your horse x and x days off" comments....both comments whilst poking at different ways of working your horse originate from the same source......someone sticking their sticky beak in where it's not needed!!! :giggle:
I've had both comments in the past, when Puz was in full fitness and lots of work, there were the "don't you do a bit much with her, when does she have a day off" comments and when Inca got to 4 and still wasn't 100% backed there were the "oh well, you really should be up there and hacking out by now" and other similar comments. Both sets of comments came from exactly the same type of people, I kept myself to myself and was usually at the yard when it was quiet, so didn't inform other liveries of my exact plans and workload for the girls so they took it upon themselves to assume what I did/didn't do and comment as they felt appropriate.
As for the last person who told me I "should" be riding Inca, I asked them to follow me to the school and stand with me while I lunged her. After watching some rather impressive airs above the ground, I asked them ever so quietly whether they fancied getting on. Funny enough they weren't so keen! In exactly the same vein, when Puz is fit she needs working otherwise she convinces herself she is a TB that belongs on a racecourse (no Puz, you are short and a little chubby!), hence the lots of work!