Dave Laribee had a great post where he details some of the qualities of an open minded developer. He also coined the term ALT.NET.
Saying things like "An ALT.NET developer would be using Castle Windsor before Enterprise Libraries ObjectBuilder.", or "An ALT.NET developer was using NHibernate before the Entity Framework." is giving the wrong impression. It gives the impression of you are either with us (good) and against us (bad). And you must follow Our (notice the royality speak) way and no other.
The other objection is that it is focusing on tools and not on a mind set. The way I see it, this is much more about keeping your head open to new approach and ideas, regardless of where they come from. In short, I really like the ideas and concepts that Dave presents, I don't want the idea to turn into "A .NET developers that seeks to use non Microsoft technologies." I would much rather it be "A developer that seeks to find the best tools and practices, and judge them on merit."
We as an industry has enough problems with the "We Are A Microsoft Shop, Do Not Write Non Microsoft Certified Code!" apprach, we don't need it in the other direction. Prejudice can go both ways, after all, and reverse racism is just as unacceptable.