Let me preface my comments by stating I do not work for Adobe, and I don't speak for Adobe. These are just my thoughts and opinions.
I believe that Adobe looked at what they felt the majority of Dreamweaver users were doing with the product, and determined only a small majority were using it for ColdFusion or ASP/ASP.net, while a large portion of the user base used it for PHP. It's probable that the majority of ASP.net developers are using an IDE for their work, and Dreamweaver is not an IDE. Similarly, they probably felt only a minority of ColdFusion developers were using Dreamweaver (I know a few personally who do, and I used to be one of them). However, since Adobe's ColdFusion team has developed an IDE specific to ColdFusion (ColdFusion Builder), it makes economic sense for them to no longer carry the weight of ColdFusion support in the Dreamweaver product. ColdFusion Builder releases are directly tied to and in sync with ColdFusion releases while Dreameaver CC is not, which makes maintaining support for new releases of ColdFusion in Dreamweaver CC another headache.
ColdFusion support has not been completely stripped from Dreamweaver (yet), though. There are a some blog posts out there from Adobe and others that show how to get the ColdFusion support working fairly close to how it did in previous versions of Dreamweaver.
Also, many ColdFusion developers have started using more lightweight 3rd party code/text editing tools with ColdFusion language libraries added on, such as SublimeText, Brackets/Adobe Edge Code, TextMate, Notepad++, and others.
-Carl V.
