No let's say motivation for the homebrewer. If he brews a RIS he may not " need " the lodo techniques as much.
"Need"? Maybe not just imperial stout.
ALL beers will benefit in one way or another. Do they need it? That's up to you, but that doesn't change the fact that they will benefit.
This statement does not contradict my "rules".
I think your "rules" assume low gravity pale lagers or ales with medium to high bitterness are prime candidates which is true. What is also true is that medium to high gravity (up to 1.090) darker beers with or without the use of more character driven Belgian strains are also candidates, it's just that some changes to accepted ingredients, recipes, process, etc. may be in order.
At the end of the day, not even the paler beers will go on without some modification to recipes and process.