I was researching which Silent Hill games included Pyramid Head, and a forum of Silent Hill fans were bashing a lot of other fans for wanting him in more games.
I’m very new to the franchise, but he’s the reason I’m now entering it. He fascinates me in a way that’s far too subliminal to analyze, for fear that my subconscious will come out and want to do whatever Freud figured it would do.
He is a pinnacle in the Silent Hill franchise, and has been personally honored by those game directors that created him. He hit the industry hard with such a unique facade, and the likes can’t be matched without looking ingenuine.
On the other hand, watering him down and including him in every game would be ridiculous and dishonorable to the Silent Hill name. However, every major game should have him, since more people will see those games. For instance, I hope that Downpour has him in it. If so, I will buy that game and cry the whole time in fear and happiness. 
Or, Konami should create a game solely for him. A one-sided game where he goes out at night and owns everything in existence, then retreats when the light returns. I’d buy that.