Revising dissertation for publication – anxiety about revision process
But I am now worried that some people might feel that I should have done this in my dissertation already to do these articles full justice. 


It's probably unlikely anyone would compare the two, and if they did notice a difference, most likely they'd appreciate the fact that you improved it in the published version.  

But even if they do think your dissertation could have been better, so what?  You can't do anything about it.  What's the alternative?  Don't improve the published version?  That would clearly be worse.  The published version is what 99% of readers are going to see, and you should make it as good as you can.


  I know that the dissertation is just a draft of sorts (that is what I was often told) and I should probably put it behind me and get on with my publications.


Yep, do that.