Given that the posted article made that comparison and it matches my experience in the industry it seemed ok to "pretend" that electronic market making was a subset of HFT.
I understand that these terms are used differently by different people, so maybe you can define what you mean to make it more clear what you think the distinctions are.
[edit] You've edited your comment since I replied to call me a shill. Full disclosure, I have worked in HFT and make no secret of it. I do not currently.
