Isn't it a good idea to make the really useful stuff part of the kernel api and maintain it for backwards compatibility? This could only strengthen the system.
I understand if features in debugfs are made by the kernel hackers themselves for their own benefit, but if those things become useful to others, they should be "productized".
After all if debugfs is used today with no warranties of compatibility, then whatever uses is will be a burden to maintain and will make the useful stuff
just a niche. Making the useful stuff a solid part of the kernel could open for new possibilities.
I would like to see some examples of
"things which are useful and safe to enable on production systems to fix whatever problems come up today, but need not become supported interfaces to preserve forever".