Not quite true. Not all hotel chains change their point values from season to season the way Choice does. Many hotel chains use a system of "tiers", and once a hotel is assigned a tier, it stays in that tier (and thus requires a fixed number of points) until and unless it gets moved to another tier (which tends not to happen more than once a year, if that).

What other hotels do to deal with high demand season is limit availabiility, rather than change the points rate. Choice, by contrast, tends to change the points rate rather than limit availability.