I have been a user since May 2005 and find this php only stuff very sad I would find it difficult to justify moving from asp to php as I have a very heavy asp development investment and many years experience. I think you are also missing out on a large number of developers cast adrift by the abandonment of the interakt products by Adobe.
How many of the investments I have made with you will become unusable by me as they are updated? I have:
Digital File Pro 1
Dynamic Web Charts
ProMaps for Google
I guess the first of these was the Digital File Pro 2 update which lost asp support.
I feel your pain as I was once a ColdFusion developer. I actually started learning PHP over a year back because the costs, alone, to license ColdFusion were getting enormous and it didn't seem to have the kind of global developer support that PHP did. I also dabbled in the flavors of ASP before deciding to fully dive into PHP.
At first, I thought it would be difficult but now after getting my feet wet and porting all of my sites over to PHP, I find it really quite easier than CF or ASP. The good news with PHP is that the licensing costs are FAR better than for either CF or ASP - as PHP and MySQL are FREE. If you have any nominal extra time on your hands, I would highly recommend taking a dip into PHP. Not only is the learning curve quick, there are so many people out there willing to help.