Could you please think rationally for once, instead of thinking that the world revolves around WinPhone 8 and Microsoft?
Sprint is losing subscribers because of a bad decision going back several years that has zero to do with WinPhone8. Heck, it might have been before WinPhone7 was going to be MS' saving grace in the mobile space. Sprint's epic failure was the decision to deploy WiMax instead of LTE as their 4G backbone. Their huge lag behind Verizon and ATT with deploying an LTE network is costing them customers. Take me as an example. I was a 10+ year Sprint subscriber tired of waiting on LTE -- plus poor coverage and bandwidth when I could get WiMax in my area and no commitment to when they would have LTE in my area.
This is why Sprint is losing customers, not WinPhone. Despite your single-handed efforts, WinPhone won't rule the world.