I don't know the credentials of this 'Greg' in any field, but he comes across as an inexperienced blowhard, that makes me doubt he could possibly have any expertise in any area. A modicum of expertise in some area and experience in developing software should ensure someone has more respect for something like nmap. It's a nontrivial piece of software and this email comes across as "I can build Reddit in a weekend".
Let's definitely debate Greg Hoglund --- someone you admittedly don't know anything about, but are apparently happy to comment about --- rather than talking about the thing this comment thread is ostensibly about.
It is frustrating that, since Hoglund appeared in the Anonymous storyline, that's all we get to talk about --- because people, like (I don't know you, so don't take too much offense) you, come out from the woodwork and hang superficial barbs like so many ornaments on an ugly, boring Christmas tree.
You are commenting about this guy's personal, private email. You don't have to like or respect him. But your contribution to this thread --- "This guy sounds like a total asshole in his emails!" --- degrades the discussion. I'm calling you on it. Please, don't be such an asshole.
I think he has the arrogance of someone who is excellent in one area, but foolishly thinks it will qualify him to be excellent in other areas. Let's not forget we're building a huge psychoanalysis on a throwaway email here.
ftfy