Having read through this board I think everyone is hitting the same point.
I don't wish to alienate anyone by saying this but, Alton Towers (well Merlin in general) employ very skilled business/research staff to help determine what's right for the park and when. As much as I would love there to be; more theming, 2 new rides and a new coaster each year we just won't get it (at this point anyway).
Unfortunately this isn't a RCT style game where we can use a money cheat, ha, but at the end of the day they are running a business, and will do what financially makes sense at the time, and if its the families who are bringing in the most income, that's what they'll focus on (I don't know this for sure, I'm just making an educated guess).
I just personally hope that this is all a ploy to gain back immense profit within the next coming years so they can build the rides/restaurants/coasters/shops/games/theming etc we have wanted for a while.
I couldn't agree more when people say they should shift their perspective to a different demographic, but all I can do now is enjoy what they're bringing in for what it is and hope someone realises how long it's been since the last substantial addition aimed at people older than (let's for arguments sake say) 12.
Ever so sorry to be so blunt, I'm kinda crap with words sometimes, and contrary to what some of my post might sound/read like I do agree with you all!
I'm new to these forums so I'll still trying to get the hang of the best way to word my view on things!