Some people are in denial of reality or play the game in such a way that the vast number of issues in the game don't bother them. Game can be fun but it needs a lot of work to get anywhere near its potential.
It doesn't necessarily require them to be in denial of reality. They can acknowledge the problems, but at the same time find the experience fun as a whole - warts and all. A person enjoying the story/acting of a movie will be more likely to forgive it having horrible camera work, video quality, etc. They'll still notice it, but by being immersed in what they do like, they'll tune out the problems temporarily. This is different from denial of reality which would be saying the movie has no problems whatsoever. The ability for people to do this differs from person to person though. I'd imagine a person suffering from OCD, for instance, wouldn't be able to overlook any small issue, and would instead allow that issue to nag at them and build upon other issues they found until they could no longer enjoy the experience at all.
In this case, the guy being sold on the game could have very well seen the problems, but at the same time, seen the potential. A good deal of people here have confidence in Stardock to correct the problems in the game, and even improve the areas that aren't problematic over time.
This is a gamble of course, but strategy games are the definitions of taking logical gambles based on expected returns later on. The people that pre-ordered the game expecting a perfect release with every little thing that was ever discussed in a dev journal, for instance, made a gamble that failed. (One could even say this was a rather risky gamble to make given the track record of virtually all games that have been openly discussed since their inception.) It remains to be seen what the return will be for people who bought the game based on the expectations that Stardock will continue to improve on it over time. Given Stardock's track record on supporting games post release, however, this seems to be a rather safe gamble to make.
That said, I do think that the game was released too early, and that there shouldn't have been as many problems at release as the game has. Just the same, I'm one of those who firmly hedged their bets on the ultimate state of the game, not the one it was released in. I still see my investment as a safe one, and hope to see it pay off - for there is nothing quite like Elemental out there on the horizon. (Civ 5, other than being a TBS, is hardly comparable.)