Your question was not a bad one, although yes it's talked about pretty frequently in other threads and across most of the hotel programs.

The typical "pay for it if you want it" reply above isn't really helpful, as if one of the main reasons these fora exist is not to understand and maximize what we get out these frequent guest / flyer / renter programs. I can understand this reply if people are indignant about not getting the presidential suite for their 2 week stay in Hawaii over Christmas.

In general most hotels regardless of brand won't admit it like the one you reference, but it makes sense that they're more willing to give an upgrade on a short stay than a long stay, and that tends to be the case no matter which program.

I will say other than "paying for it" is to email the hotel in advance with a polite and specific email (i.e. name a specific reasonable room type you'd like) asking for an upgrade.