I really don't know. I wish I did. Things with my wife on the whole have improved dramatically in the past couple of weeks, including more affection from her, more empathy from her, etc. I've been giving her a lot more space, but I haven't stopped 100%. I send her 1 or 2 texts a day while we are both at work. Of course, I know that it takes minimal effort on her part to send a quick reply when she gets a text, but for some reason she she often doesn't. I don't let it bother me, because it's so obvious that things are just fine.
Maybe it is a control thing. From my viewpoint, her motivations don't matter much in the grand scheme of things. I wanted to tell her I was thiking about her... she gets the message... any reply from her is optional. I like it when I hear back from her, otherwise I just wait to see her when I get home. I have to rely on my own confidence here.