Remember, when you talk about mining profitability you have to assume current exchange rates, not exchange rates in the future.
Really, I'm not sure that I have to assume anything to be quite honest.
I see what you're saying. Short-sighted miners who sold as soon as they mined really got a bum deal, and we're doing better today then they were, but that's not really the point.
If I do assume current exchange rates, and look back at people making 200BTC/day on 4 computers just using 65W core 2 duos before the GPU miners were available, then (provided they waited until now to sell their coins) they were making $1800 a day for an insignificant amount of electricity cost.
I know there's some people out there that saw the exchange rate creeping up and just kept the coins and still have them today, so you can see where the jealousy creeps in... It's much like the gold rush in America during the 1800s. Some dumb prospectors were selling at £1 and £2 an ounce, which seemed amazing at the time, but then a few years later prices skyrocketed to 10 times that, so those that hoarded their gold became super rich.
Of course, unlike gold, if anyone did try to sell $1M worth of coins all at once the exchange rate would crash, as there simply isn't the demand there right now, but if they did it slowly they could really rack up some serious $$$ and for what? Simply having the good sense / luck / foresight to start mining in 2009 instead of 2011 like me
I think it's an incredible story and I hope someone takes the time to document all this properly, it will make an amazing movie.