I'm not very happy that anyone can learn and use rituals. To me, the greatest and most mysterious powers of wizards, clerics, druids and other magic users was their ritual magic, not just the spells that blow things up. Now those things have been offered to everyone. This isn't just about martial classes having rituals, it's also about wizards casting raise dead and clerics casting leomund's secret chest. It just ruins so much of the flavor that differentiated them, IMHO. Now, anyone can, with the expenditure of at most 2 feats, have access to many of the greatest powers of wizards, clerics and druids from previous editions.
For the same reasons that characters have different roles in combat, I liked how, in previous editions, different magic users had different specialites and roles outside of combat. If you needed a disease cured or a special blessing, you went to the temple (or your party cleric). If you needed your keep magically warded or something hidden away in a secret chest, you went to the wizard guild (or your party wizard). Now, anyone with the ritual casting feat and enough money (or anyone that can afford the appropriate scroll) can do any and all of these things.
I guess one can say that the power of a ritual is contained within the ritual itself. But to me, that just cheapens what magic is. Magic has always been a very difficult thing to learn and do. It wasn't just about learning incantations, ingredients, prayers or formulae, it was about learning how to harness your own personal power and mental discipline (or faith) to do amazing things. Now, all of the power of a ritual is in the tools rather than the user. And that is just not how I think magic should be.
Now, the only type of magic that wizards can truly call their own are their simplest of spells. Shooting magic missiles and lightning bolts is something only wizards can do, but anyone can learn to cast scrying, magic circle or teleport? If anything, it should be just the opposite, IMHO. Ritual magic should be harder to do than the simpler stuff. And to make it something that any old joe can pick up for at most two feats just totally wrecks how special and powerful these types of things are.
But oh well, I guess it's easy enough to house rule that only divine casters can use heal/religion rituals and only arcane casters can use arcane rituals. I just wish I didn't have to.