How dare you question me!
Haha, just kidding.
Seriously though, here is my reasoning behind the idea:
1) Standard days - makes it easy to calculate your consumables, and since, as you pointed out, a 2 night trip will use the same base gear as a 2 week trip, it will be easier to base the standard on a shorter trip length, and one that is probably the most common.
This also helps account for weights that otherwise go unaccounted for. Say your baseweight is 10lbs, and my baseweight is 10lbs. But, you use esbit and carry 6 ounces of fuel for a 3 day trip, and I use a canister stove and carry 1 pound of fuel for a 3 day trip. See, right there is unaccounted for weights that are a big topic here, but don't find there way into baseweights. Same for guy who uses efficent alcohol stove vs. someone who uses super fast but fuel hog alcohol stove.
2) Water - while this won't be relevant to me and you comparing weights, since the water will be the same, it will help people who are new to backpacking, or just new to BPL compare to us. It will also be helpfull to those that don't own a gram scale, and don't know about geargrams.com.
The whole idea behind my "standard" is that anyone and everyone can compare there "BPL standard" weight to someone else, and be comparing apples to apples. As it stands right now, you have people listing "baseweight", "skin out weight", "trailhead weight", "bone out weight", etc. etc.
With the "standard" any Joe Schmoe can step on a scale right before he leaves for a trip and have a good idea of how he compares to others, and where he falls in the traditional, UL, SUL, XUL scheme of things.
Another thing it would do is help account for different food preferences. Jimmy only eats olive oil and peanut butter and thus only carries 3lbs. of food for 3 days, while Rebeca brings two steaks, and a repackaged bottle of wine on a 3 day trip, and wonders why her trail head weight is 35lbs. despite her 10lb. baseweight. Well, with this system, she can better figure out where the extra weight is coming from.
Anyways, it's just an idea I had that would make things easier for people to get a better understanding of what they are actually carrying on the trail.
Maybe I should give this topic its own thread, if there is interest in discussing it further.