I have been playing since I was on iPhone 4, moved onto 5, and now 6. But no problem for any of them, no crashes or anything. I'm usually on wi-fi when I'm at home, but also used 3G or LTE now when I'm outdoors. But still no problems. So I don't know why you have experienced crashes, and like I've said before, I never experienced it when I'm on IOS and doesn't matter what I'm using to connect to the internet.
Anyways, I do agree that TL is more focused on new players, with so many new dragons introduced every week, none of the older players, especially those like me who have fully filled every spot on the island, will want to keep up with new dragons every week. A lot of my older neighbors who got many Diamond hybrids even before I did, they have left the game already, despite doing better in breeding than most players at that time, so it shows how frustrated they are at the game.