Can someone explain to me how Hammer is outdated? Sure it doesn't have realtime rendering, but besides that what is outdated.
Also, DOTA was a mod that VALVe bought.
-Porting models to Hammer and getting them working in game is incredibly tedious and time-consuming (writing qc files, fucking about with smds), where as for UDK it's save as .fbx, load up UDK, import, done.
-The workflow is pretty awful. All the tools hammer should have had, have been created by a third party. (VTF Edit & PS plugin, HDRShop, Source shader editor etc etc.)
-The ridiculous lack of dynamic lighting is a killer here. Not even to have the option to have orthographic shadowing is silly. All we are reserved to is spotlights. Even though many mod teams have hard coded this into their bases, it's not available to do the same on newer engine versions due to Valve releasing them as authoring tools.
-To basically fake a dynamic sun with shadows maps projected onto the whole environment in CSS, you would have to bake shadow maps onto every single model and surface in something like 3DS max (using mental ray and the sky/sun options)
-Sure most of us can work past not being granted with real time editing and rendering, and source is very good to whip up ideas fast, seeing as the brush tools are so easy.
-The limitations to map sizes is disheartening and the very reason Ivan's Secrets switched.
-How many times have Valve broke the tools and hindered progress for mod teams?
I find it hilarious when somebody responds to this kind of thing as 'oh you are all whining, I can make stuff fine, get over yourselves). If you have your head screwed on, you will see that the community is beginning to crumble. All the 'big' mods are either: non-existant, switched engine or gone indie. There is hardly any backbone supporting the community to keep it stable for that much longer.
Dear Esther is pretty much the only big third party indie game of recent that remains on the engine, and Robert Briscoe made his concerns about the limitations many times.
And the list could go on......