A while ago there were a couple of "modders" who decided to intentionally screw up people's games. They created mods that, initially, didn't seem to do much of anything. Then one or more npcs would start spawning and not stop until the game crashed. Another one, iirc, suddenly made all the npcs heads the size of Macy's Thanksgiving parade balloons and spawned more, until the game crashed. There were more; it took the modders a lot of time and effort to track down how, who, and what. I can't find the thread that had a post from bridgepiece on how to detect malicious mods, but it used to be here, and it was needed because of idiots who thought it was fun to crash people's games and corrupt their saves.
And this was on pc. If they managed to do the same thing to a console, it wouldn't be good.
Of course not... but that's the risk of installing mods!
You need a SHORT (ie; readable) EULA and warning that installing mods CAN break your system and you accept this risk by installing them.
Then have a feedback and rating system... so people who are less experienced can look at mods that have been downloaded several thousand times with nothing but good reviews and no problems found.
Furthermore... the list of available mods to console could be restricted by BETHESDA (not ms/sony)... to only provide mods that have had at least x downloads with y positive reviews and no game destroying glitches found.
THere would still be no guarantees of security... which is why sony and ms will never let it fly... but it could theoretically work that way.
The problem is that your avg consoler is... sorry (and bear in mind I AM a console player)... a technological idiot and expect everything to just work for them out of the box.... Sony and MS know this and don't want to deal with their ignorance, and so capable, intelligent gamers who could responsibly use and gain GREAT benefit from more open community options are left in the cold and told to "just buy a PC"
Well I'm poor dammit.... and not only that but I prefer FPS on gamepad (with EVERYONE on gamepad... doesn't work so well when everyone else is using omuse aim

)
It's just a shame really.
I'm scrounging together money... or trying to anyways... to hopefully build a PC this year.
Doesn't change the fact that this big brother mentality is short-changing console gamers