How's that? I use Paint.NET when I'm on the road to edit .psd files and it works fine. Actionscript can be written in a text editor if you so desire. Dreamweaver's html and I couldn't even list how many third part pdf editors are out there. So how are designer/developers locked into the entire CS suite?
Many of the features in the .psd format are undocumented and proprietary, and some are not backwards compatible. Up until CS5, the .fla format was proprietary (it is now zipped XML, and I understand that there are undocumented features there too).
Ever try sharing an indesign file between different versions? You can't, even if they are one version off. Sure you can export XML, but again, it often doesn't retain the same layout.
Fireworks adds proprietary information to the PNG format, so you can't open those files in other editors without losing data.
This just sounds like a poor sport who wasn't invited to the same type of party they are already throwing.