It is an odd choice, and it's also very confusing, as they mention specifically directly exporting into DOTA2, but then it also says this: "Purpose built for the STEAM community, MODO Steam Edition delivers a complete content creation solution for the Source engine" Source engine, and not DOTA2, so perhaps they're riding…
Just a side note. You can add custom animation to DOTA2. But full version of modo also doesn't really support exporting bones and animations in FBX, so it's hard to complain about it ;p.
What is worse about it exactly? As far as I can tell it has all of the modelling and texturing tools that the commercial version does. Given the stated goal of creating items for DOTA2, I'm not really sure what more you would need.
The description says that it is specifically for people making DOTA2 items rather than the modding community at large, which is an odd choice on the Foundry's part. I'm not entirely sure why anyone would pay for software like MayaLT or the comparable Modo version when Blender is free and just as capable.
A post from the steam forums by a dev: "MODO Steam Edition will have the ability to export to a limited FBX. It is limited to non-commercial use outside of creating and selling items in Steam Workshops. Re Animation: Currently there's not a lot that you could do with custom animations within the context of Steam Workshops…