youngbutnotdumb thankyou for posting this - we had this very problem when my dad was in a care home, total lack of stimulation. When we complained to the boss - he went and showed me all the board games they had and said that these were available to the residents at any time - FFS the residents didnt know who they were, what time of day it was, what way was up - how the hell were they going to play board games . I know that it isnt the case with all home owners, but this guy was in it for the money and the residents imo were neglected. We complained, so, my father was evicted and we had to move him at short notice to a place that was nigh on impossible for my mum to get to visit him. It makes me sooooo angry. Fortunately the new place was much nicer and they did seem to care. Although i have to say, none of the places i went to did as much as they could, activity wise.
My advise to you would be, speak to your boss, but do it in a round about way - maybe propose that you instigate an activity a couple of times a week. Even if it is throwing a foam ball around, playing skittles, something like that - you would be amazed at how much differnce that could make. People with dimentia often have quite lucid memories of their younger years, so some sort of nostalgia based activity - music is good for this. A tea dance?? Get some paints out, etc I know it is difficult becuase there are more immediate needs to be attended too. But the homes should take on more staff, i dont think there should be financial excuses - the guy who owned the home where my father was drove around in a flashy sports car and i bet he didnt go without anything, but his residents were denied basic dignity - um, can you tell this is something i feel strongly about!!
If you feel that your concerns aren't being taken seriously, you could anonymously phone the Social care ombudsmen or is it social care directive, i cant remember, but social services know - that might be enough to prompt a spot check and this might well be addressed then.
Sorry for hijack, i hope your grandad is on the mend OP