It's about the current encryption allowing CDMA carriers to have the same thing GSM carriers have for years, and how many think SVDO is a myth for CDMA!
Also, if you mean Verizon and Sprint account for nearly 95% of the postpaid CDMA market, you are failing to acknowledge US Cellular, C Spire, nTelos, and Credo For about 25% of the post paid CDMA subscriptions, while CDMA carries about 65-75% of the prepaid side of things, where most of the numbers go to Virgin Mobile, Boost, MetroPCS, and The CDMA services of Straight Talk, and I am not forgetting smaller carriers that add to the numbers.
Combine them in total for lines, and CDMA has about 2/3 of the cell phone market in the US (including Puerto Rico and USVI), which makes it two times bigger than GSM based lines. This might not be the norm internationally, but this has been the norm for many years in the US Market, whether WP supporters in the USA who act as CDMA (more like Sprint) haters like the facts or not.
Call me a CDMA ****** if you wish, but I speak with facts, not with unresearched rants, and sooner or later more people will point at the lack of real support for CDMA as the main reason Windows Phone has been a major FLOP in sales in their home market, The United States of America.