Think about it for a minute, what if you really managed your life this way, what if we assigned everything a relative Shabbath-value? It would change our lives drastically. In truth, as Jews, we are meant to value everything in terms of its spiritual potential, but that is still a relatively distant and abstract value-system. In place of that, Shabbath is very concrete. Either you can use it on Shabbath or you can't.
[At this point in the midst of my brilliant flash of insight, I said, wait, what about my Tefillin? I can't really be expected to hold myself to a value system where my tefillin have no value. Well, you will be happy to hear that Tefillin, while it is not a mitzwah to wear your Tefillin on Shabbath, can be worn on Shabbath in specific circumstances. Still, since there's no mitzwah to do so, our new way of looking at value seems to seriously devalue my precious Tefillin.]
We can actually do this same re-evaluation with each and every mitzwah. (In some cases halachah has done this: discussing the value of non-kosher food, etc.) If we were to take this all the way through to its end, we could, through evaluating everything in our lives through the eyes of each of the mitzwoth, arrive at which things have intrinsic value to us, and which are empty mitzwah-calorically.
I can't imagine I would sit around watching TV if I was really aware of how many mitzwoth (613) derive no benefit from my watching it.