Pat,
I agree with you that the .45 will do a majority of the jobs most shooters are likely to ask of a standard format semiauto. (I carried an HK USP Compact .45 for a couple years and it's still one of my favorite pistols.) I also agree that the .45 is much, much more popular and therefore there are more platforms available and ammo is cheaper and easier to find.
I think what most 10mm supporters here are saying though is that the 10mm is a much more versatile cartridge. When pushed to it's true power potential it ranks with mid-range .41 Magnum loads, and yet can still be downloaded to .45 +P, standard .45 and .40 S&W loads. As for recoil, more power is going to translate into more recoil when all other variables are kept equal. If what you're looking for is a hot hunting or "woods" load then the power that's pushing that bullet harder and faster down the barrel is also going to be pushing harder and faster at you. If you don't need that much power and would prefer something that is similar in performance to a .45 or .40 S&W then you're going to also get a similar amount of recoil.
When it comes to ammo and gun availability you are correct about the .45 being much more popular and therefore much more common. The 10mm can be found (either new or used) in a lot of the same platforms as the .45, but there are definately some guns that are not currently available in 10mm such as the Sig 220, Beretta Cougar, Ruger P90, etc.
When it comes to ammo the "big three" (Winchester, Remington & Federal) all continue to load the 10mm, but these loads do not take advantage of the 10mm's power potential and use relatively antiquated bullet technology. These marketing decisions that are being made by the major gun and ammo manufacturers has created a niche market for the 10mm which companies like Dan Wesson, Tangfolio, Double Tap, Texas Ammo, Pro Load, etc. are now capitalizing on. I assure you though, the "big boys" are watching and if interest in guns and ammo for the 10mm continue and they see there is money to be made then they will not hesitate to introduce new offerings for the caliber.
I hope to keep this discussion objective and "even tempered." I do not agree with a lot of your assertations, but I understand where you're coming from and you definately have the right to share your opinions and experiences. Regardless of what you say though, I will continue to be an unrepentent 10mm fanatic!