PC mods already have to be updated to support the consoles it wasn't a one to one conversion or anything to start with. How would it make Beth look bad they could release it with limits and announce what they already have Sony limits their capabilities. That way they point everyone at Sony without punishing the ps4 players.
No, you don't. The Xbox just has a 2GB limit. There's no extra support which has to be baked in. For example, the Xbox supports all the same graphical mods which are on PC even if it tanks performance.
Whatever got written up and agreed between the two parties will of essentially creating this all or nothing scenario. From the looks of it, Bethesda wanted untangible full support for mods, and they couldn't support that, so they backed out. If Bethesda come out and say, sorry mod contributors but you need to do these set of tasks which these propitiatory tools to get your mod on the PS4, you're going to piss off the creators, piss off people playing the game and just make yourself look bad for what seems to be a half-baked solution what you yourself have implemented rather than the restriction of the platform holder.
The PR statement which we got a while back about this would of been a reactionary response from Bethesda to go public to try and kick-start Sony into giving them what they needed, and even that didn't make them.