One reason why those various systems have powerful history is that they're intended to be used for animation, so instead of only just building a model the app is oriented towards building a kind of system of various parameters which can then be altered over the course of time to make animations.

The problem is that whole process of "building an animation system" like that can have a major impact on UI complexity, you don't so much just do simple actions, everything that you do revolves around manipulating that animation system. This generally tends to lead to a fairly complex UI, someone who wants to use it has to know a lot of stuff for how the whole thing works.

For MoI I do want to provide some deeper history editing functionality similar to that, but as an optional thing so that it does not make the whole application more difficult to use or force you to go through extra hoops just to do simple modeling tasks.

Actually, one of the reasons why people use MoI as a supplement to those kinds of programs is that MoI is simple to use for modeling, and one of the reasons for that is that MoI does not try to make the process of constructing a model to have all the same UI and process that goes along with setting up an animation system.

- Michael