Because there is no guarantee of interoperability.
With mods from Nexus and friends, I have no expectation of compatibility between gratis mods made by people in their free time. (even though mod authors usually go to great pains to make sure they’re compatible with most anything that isn’t another mod doing the same thing)
If I’m paying for a ‘mod’ (really just DLC) - I expect a paid level of support.
I have no plans on buying any mods from Bethesda.
Why?
Because there is no guarantee of interoperability.
With mods from Nexus and friends, I have no expectation of compatibility between gratis mods made by people in their free time. (even though mod authors usually go to great pains to make sure they’re compatible with most anything that isn’t another mod doing the same thing)
If I’m paying for a ‘mod’ (really just DLC) - I expect a paid level of support.