Morrowind: 2002
Oblivion: 2006
Skyrim: 2011

Aprox. 4-5 years between each game. I don't believe that Bethesda starts working in the next game even a year after the release of a TES game. Maybe it does take a lot to make a huge game like that, specially a fully voiced one as is Skyrim. But, in my opinion, the gaming world isn't up to be waiting 4-5 years for the next game, much less a franchise as immersive as TES, some of us can die in the waiting in a traffic accident. Maybe they are aware of this and this is why they are throwing us TESO.

I want to know your opinion, if i'm the only one thinking that TES games should be released in shorter periods of time. Or maybe some of you think that is better this way.
Of course it has its advantages, but at wich cost?

It's better that it takes 4 or 5 years to create a new Elder Scrolls game. A shorter dev time means less stuff and smaller world

I agree. The longer it takes the better the final product will be.