XNA was quite far from what Unity is. Unity gives you a full engine, whereas XNA was a framework and you had to build the engine yourself. It was a great little library, but it was painful for unskilled software developers (myself at the time) to use it compared to Unity's WYSIWYG and property lists you could modify, not to mention all of the things that came with Unity that you'd have to build custom in XNA.
That's not to say Unity is better, it was just easier to use.
XNA was quite far from what Unity is. Unity gives you a full engine, whereas XNA was a framework and you had to build the engine yourself. It was a great little library, but it was painful for unskilled software developers (myself at the time) to use it compared to Unity's WYSIWYG and property lists you could modify, not to mention all of the things that came with Unity that you'd have to build custom in XNA.
That's not to say Unity is better, it was just easier to use.