I've been in the domain (accumulation) business a while and something struck me today, I domain the same way I used to play Monopoly.
I treat sets as a good thing (like my London name set). I have a few domains that I would never sell (generics or those with websites that the income is regular and in a niche). I really consider them like Park Lane and Mayfair.
If I could, I'd own everything, I never sell a domain or a property for less than I paid for it, and only consider developing when no other properties catch my eye. Both I treat as a game, up until recently where I'm questioning more of the decisions.
Sure Monopoly and domaining are both business, but I guess that there's an evolution I've gone through with them both being a game or a hobby, to understanding a little more about the business behind them (investments, opportunities, opportunity cost, resale value, income, development).
I think it's important with most things in life to be reflective every now and again. Domaining is no longer Monopoly for me - well at least I'm changing my strategy from how I used to play Monopoly. I now just need 1 or 2 sets with a few nice hotels and then I'll be happy! (I don't need the stations and the utilities).
How do you play Monopoly or domain? (yes I did turn it into a verb)
Mark Twain advised "Make your vocation your vacation" end quote.
If you enjoy what you do, call it what you want, a hobby, a business, a game, it doesn't matter, if it's rewarding, particularly financially rewarding, then I would keep doing what your doing and don't over analyse.