Turn-based vs. Real-time
Not quite there yet
Before we get to a point, I should preemptively shoot down a point I know that someone is going to fire at me. Since gamers decide what kind of games they like, and if they don't like turn-based games, there's no market for TBGs, right? After all, what right does a publisher have to raise prices, complain about income shortfalls or cut projects if the publisher makes turn-based games even though gamers aren't buying them, right? The public knows what it wants?
Well, remember - a lot of people thought that CPRGs wouldn't sell anymore. More importantly, it was the general public that thought that. We were uninterested in CRPGs, so why were publishers wasting money making them?
Just because everyone does something, doesn't mean they are right. What's better, a manual transmission or an automatic? The manual. In general, they are more reliable, more fuel efficient, they help accelerate the car faster and they give the driver much more control over his vehicle. Even better, a manual transmission is much cheaper - as much as $1000 on some cars - than its lesser counterpart. An automatic does have some advantages - such as ease of learning and ease of use (especially in hilly/mountainous areas), but if more people took the time to learn manual, they would save themselves a fair bit of money and have more fun driving their cars.
The public is wrong?
But we're lazy. We like the easy way out. We like Windows-like user interfaces, even though a Unix, Linux or even DOS command line can be quite a bit more powerful at times. We like to have things done quickly. Not many people like playing 20 minute periods in NHL 2000 or 15 minute quarters in NFL 2K1. They want fast games, but with the same high scores.
We want all the fun and intricacy of strategy games, RPGs and tactical combat, without the waiting for turns, without the need to plan every single last move. Are there many advantages to this setup? Sure. But a great deal is lost in the turn-based to real-time conversion. Some games - like those war-games I mentioned - quite likely can't work in a real-time environment.
Ticking away
Turn-based games aren't perfect, and they aren't necessarily superior to their real-time counterparts. There are many drawbacks to the turn-based system. The biggest and most obvious one is time. TBGs are very time-consuming. To plan out all the moves of your characters in an SSI gold box game, or to move every trooper in X-Com, or (especially) to plot the movement of divisions and corps in a war-game - that's brutal work. It takes meticulous planning, concentration, forethought and a great deal of time to actually execute once you are done thinking about it. For many people, this kind of planning and thinking is satisfying - it gives you a feeling of a job well done, they you put all your effort into it. Then again, for many people, driving a car with a manual transmission is fun and efficient. That doesn't mean they hold the most popular opinion on the block.
But, even though cars with automatics outnumber manual-driven vehicles, there is enough of a market to keep the manuals around. Turn-based games offer enough advantages that they deserve a market - we just don't see it yet.