Really? First, I'm not trying to disagree or question whether or not you're correct. I'm merely sharing what my understanding has always been...
I've never heard that. I was always told you needed the wine to be in contact with the cork so the cork doesn't dry out. If the cork dries out, it can shrink enough to all air into the bottle. Of course, this is a bad thing! By tipping the bottle, the wine will keep the cork moist and maintain it's seal. You don't have to store them on their sides forever, but it was my understanding that you want to at least tip it periodically to re-hydrate that cork!
This was what I understood as the main advantage of the synthetic bottle stopper over cork stoppers. The synthetics will not dry out, so you can store the bottles vertically. Now I'm confused.
I'm not a wine expert by any means though. I did go through a wine phase for a couple years. I never got into the expensive wines. My interest was to find the bargain wines that I liked. I found several that I really liked that were only $6-7 a bottle on sale, so I would just buy a case when they went on sale.