I thought a while about this. While I understand your feelings I also think, it is not the right decision from the business point of view.

Monopoly:
Using tools from the leading (monopoly) company never is a bad idea. Most customers are using it, many developers are using it. You have a good base, a big knowledge base.

C#1.1 only:
While this is only a little issue for a programmer, it is no issue at all for your end user. The gamer, playing your game, is not interested in namespaces. The game matters in the end. And C# 1.1 is still better than all these script languages.

let it grow up:
I see no other indie engine with more platforms supported. And there is probably no better workflow.
It will grow up but then it will be more killer than it already is.

At the end it is really hard competition to all indie engines. GarageGames and Torque is comparable to it and now they get free competition. Even free engines like Irrlicht and Ogre3D get quite impressive competition with much better workflow.
This will change the market for sure.

At Dexsoft we have to support Unity models and packages more than we did in the past. Most indie developers will be there in the future.