You made your point. If what you are doing is working for you then keep doing it. Also, it is not just about definition but the psychological or mental approach to domain investing. So far, there have been a lot of posts with valuable info.
I am not trying to teach here. The prefix to this thread is "opinion". Everyone is entitled to it. Since 2000 I have sold hundreds of domains in the low to high X,XXX range. I have registered a lot of duds. I have sold strong domains at a ridiculously low price because a more experienced domainer was able to bamboozle me. I have allowed good domains to expire and get snatched in auction. Mostly in my early inexperienced years. In those years I acquired a modest portfolio of many poor names and lost a lot of money in renewals until I smartened up and let them drop. Now my portfolio is much smaller. I have become much better at recognizing good deals on the aftermarket, auctions, and new reg's. I learned how to do due diligence and investigate domains, whether previously reg'd or new reg's. So I think I have put in the grind, earned battle scars, and have learned over the years to know what I am talking about. I am not a proactive seller. I register both for resale and development projects. All my sales came from inbound inquiries.