To say it isn't possible is ridiculous and lazy, sorry that's just a total crock.  Would it present challenges?  Sure.  Is it beyond the scope of coders everywhere?  Absolutely not.  Restricting map sizes based on assets used, or other such tricks would be incredibly easy to do.  No, it wouldn't be like PC modding, where you'd have full access to all the resources.  But, you could have a basic framework that allowed the users to create without overloading the system.  Injecting your own sounds for stuff, or enemy models ala Doom?  No problem.

Besides, even if they were given more access (which would be possible if developers simply cared enough to request it from Sony/MS, it would definitely require an en-masse request, though), there are some modders out there more than up to the task of metting out the resources they have to work with.  One merely needs to look at the Stalker Lost Alpha mod to know devs/pubs aren't the only ones with brilliant designers.

It could be done, if they cared enough too.  They like their little cash cow revenue streams though, hopefully, they also enjoy watching studios crash and burn as their cash grabs fail more times than their successes.  But, I guess the silver lining there is there's always mobile.  I do not absolve devs/publishers from falling in line with Sony/Microsoft/Nintendo in this closed network bullshit, they signed on because they saw dollar signs, nothing more, nothing less.

Again though, this is my wish list.  You don't have to agree...I'm not asking you to.  I just think mods would open up a whole new world for consoles, and a great one at that.

Alright. I respect that it's your wishlist, but please don't blame the devs. It really is impossible for them to make it work, because the resources required for serious modding are system resources, which the console makers don't want you screwing around with. I'm not saying that your opinion is wrong, just that what you're suggesting is impossible for devs.

Baby steps.  I realize it will take effort (I still disagree in the 'impossibility' statement), but it's a worthwhile effort, can't start with a full fledged PC version of modding, that's fine.  But you can certainly start on a smaller scale.  As the systems are created, it can become more complex.

And I don't absolve the devs who jumped ship from PC, and an open modding, map making and MP server environment, for the dollar signs they saw on console.  That they went to console, is fine, and certainly expected.  That they butchered PC, to make consoles look better, makes them every bit as complicit.