If you don't have a (high enough) status, why should they upgrade you? They won't even upgrade you at 12am check-in even if you would be the only guest in the entire hotel and they have 10 empty suites.

Did you ever consider getting status X with brand Y if they offer a fast track that fits your scheduled travel plan? Or why don't you consider being part of promo N of brand O that will end up in a lot more points or even free nights? Why being loyal if all the chains will devaluated your points in Z months anyway and you won't get any benefits otherwise.

There is nothing wrong with sticking to a chain to collect enough points for your next reward night. But most often this will take many, many nights that might or might not be worth it. Or you stick to a program since you value them more for a similar price as another program. But that's in your best interest. Hotels will never work in your best interest unless you pay heavily for it.