Cyclocross - Why the more upright position?

I keep reading about lowering my seat 1/2 to 1 cm, and raising bars the same on a cross bike. I rode my cross bike for racing and training all season last year (including group rides and a century), and being tall (978mm cycling inseam), 10cm bar drop is pretty normal for any bike that i ride (stem flipped up with spacers under). So I have set myself on a quest for a taller HT bike, but I am not sure why. Sure, my back gets a bit sore during races, but whose doesn't? Does the upright handling change weight distribution or handling characteristics? Should i just give up and keep riding large bar drops and resign to the fact that i am too tall for this sport short of custom.

A *slightly* lower than optimal saddle height helps with dismounts and remounts, and won't hurt your pedaling dynamics too much in a racing situation where you are going to be all over the saddle, out of the saddle, off of the bike, back on the bike, rinsed with mud and repeat... it just doesn't make as much difference. By contrast, you'll feel every millimeter of your saddle being too low on a long seated road ride.

The more upright position is an oversimplification, but a convenient one. The biggest thing is weight distribution rearward to deal with offroad obstacles, steep descents, etc... to keep from going OTB and to be able to shift weight around without disturbing the steering too much.

Don't buy into the old garbage about sizing down for 'cross. At your height, you will need every millimeter of headtube you can get. I'm 6'2" on a 60cm frame, and I run my bars just shy of saddle height, so that means lots of spacers and a re-evaluation of stem length once you get it high enough. It looks funny, but it works great.

Then again, I'm no expert, and I'm sure lots of guys will reassure you about how you can race cross in a flat-back aero tuck. ;)

+1 sunset1123, except that changing saddle height isn't about remounting (1cm isn't going to make it any easier) but about bike handling.

Think about it this way. These two bikes:
http://www.giant-bicycles.com/_generated/_generated_us/bikes/models/images/550/2011/Trinity_Adv_SL_0_comp_wht_blue_72dpiWIDE.jpg
http://www.giant-bicycles.com/_generated/_generated_us/bikes/models/images/550/2011/Glory_0_smoke_tint_72dpiWIDE.jpg
are designed to go as fast as possible, but over different kinds of terrain. A cross bike should fall somewhere in between, right?

Saddle height is worth experimenting with, but you might decide to keep it exactly the same as your road bike. If you have your road bike deliberately set up to be very aerodynamic and aggressive, you should definitely raise the bars for cross. OTOH some people have pretty moderate setups for their road bike and may want to change the cockpit only slightly (like maybe tilt back the bars a smidge).

You gotta do what works. Adam Myerson has joked that Francis Mourey's bar/lever setup is like something out of the 1970s, but he rocks it:
http://1.bp.blogspot.com/_W6PdCSPYbOM/TJ1kjKQq8tI/AAAAAAAACVs/_EZPeXPjJis/s1600/Moureys+CX+bike.jpg

Hmm I have my cross bike set up with a little more drop than my road bike. I like to get some weight over that front wheel for traction. I don't know if it's the right way, but it made sense to me...