It's all about "Instant Gratification" these days. Most people that don't understand RTS games say they are "Boring", and take way too long to play. They would rather play FPS frantic point, and click fests. Where you instantly start a game guns blazing, and you have ZERO time to sit back, and enjoy the view.
RTS games are anything but "Instant Gratification". You have to plan ahead, build, anticipate your opponents moves, and counter them. Meanwhile come up with a plan of attack of your own, and execute it. Just like huge games of Chess. Most RTS games are like this. With the exceptions of games like Starcraft. Where whoever can rush with the most units first wins.
Blair may also be referring to PC game market in itself. Consoles are taking over the gaming market, and touch screen "Pads" are replacing PC's. Most PC's i see in the local shops are now "all in one" units kinda like the IMac of the 90's was, and you quite literally can only build a standard gaming PC from parts ordered online these days. The crap in stores just doesn't cut it any more.
It will be interesting to see how PC sales themselves are.