Originally Posted by Sciolist
I don't think this is necessarily the case - alternate Walter is almost certainly a nasty guy, whilst our side's Walter didn't know the outcome of what he did. Our side don't recognise what they're doing, whilst the alternate side has a much better idea.
Walter had a pretty good idea what opening that doorway would do. Even Nina knew there would be serious consequences.
I see nothing to suggest Walternate is a nasty guy. He may have the doomsday machine that will destroy our universe but it can easily be interpreted as an retaliatory attack upon us to stop the inevitable destruction of their universe from the rips in the universe.
If things were reversed would we not do the same? Is this any different to the nuclear deterrent?
Also our Walter is an extremely nasty guy, he is basically identical to Walternate. This was shown when he had the pieces of brain reinserted into him with the dramatic personality change to the guy who experimented on unknowing subjects including children. Walter as he is now is pretty loveable but dont mistake him for being more a mad scientist than an evil genius.