My opinion is that it is all to do with her abandonment issues. Her children will never leave her and she is scared that she will do something to make them want to go.
In her rare moments of self reflectiveness she'll acknowledge that she doesn't want her kids to "hate her" although that's only in the big discussions... . me wanting to move from the house they grew up in.
It's the double standard that's toughest to deal with... . Her getting 90% things her way and arguing that I want everything my way. The black/white thing won't let her acknowledge anything that was discussed more than 2 minutes ago.