FI and SHS are not extended stay brands; they are limited service hotels. RI and TPS have kitchens and dining tables. FI is just a room with a microwave/fridge. SHS rooms have two distinct areas (bed and living) in an open single room with a small bar area with a microwave/fridge and sometimes a sink. You've likely never stayed at these brands if you think there are similarities. Trust me, these are very different types of hotels.

You've probably never stayed at a Gaylord property, either, if you do not recognize its unique niche. The four existing Gaylord properties (one more set to open soon) are among the largest non-casino hotels in the US with unique convention/resort capabilities not found in other Marriott branded properties, save, perhaps a couple Orlando properties and maybe one or two others in the US. There is a definite niche there. SPG has nothing like Gaylord.