Windows Phone Apollo rumoured for a mid-June 2012 launch
I am a developer. I would say you are not entirely incorrect, but you have oversimplified the topic. In my post I discussed the effect of WP supporting a lower screen resolution, which is why I only mentioned hardware fragmentation. However, fragmentation can result from hardware just as easily as it can from software.
Yes, some hardware differences can be abstracted away entirely by the OS, meaning 3rd party app developers can safely ignore them. Supporting a higher screen resolution while maintaining the same aspect ratio would be one such example and hence isn’t considered fragmentation. However, supporting a lower screen resolution is a very different endeavor. MS’s Silverlight API will probably keep an app running on such an device, but the user experience will be very different and likely unbearable. Developer intervention will be required and likely a lot of it, no matter how good MS’s SDK’s are. That requirement for intervention is what constitutes fragmentation… both types of fragmentation are “real”.