You can still pray at altars and wear amulets. It does not take away. All you do is piss on my ideas. You dont like em then [censored] off because you are bringing me down
What is your problem? I'm telling you a particular problem I see with your idea and you take it so personally. I'm not attacking you so don't get defensive.
I find your idea restrictive because if people are going to react to the fact that you hold allegiance to a particular deity, you cannot ever change that allegiance, which I feel is restrictive. If you've ever had a crisis of faith, you'd understand that your beliefs are not completely set in stone, and you may discover another system of beliefs is right for you. With the current system (i.e. the ability to get blessings both from amulets and from praying at shrines), you are free to change your beliefs whenever you wish. You can always be a loyal follower of Mara, or you can decide to follow Arkay instead.
However, under your system, you would be locked with a favorite from the moment of character creation. If you carried this through with extra dialogue options and whatnot, you would no longer be able to role play as someone who has a crisis of faith (Like say Erandur or Shavee [though that's more a crisis of morality]) because characters would still react as though you served whatever god you chose to follow when you started out. That's the problem I have with this idea. I'm not opposed to the concept, but the implementation right now would be very rough and unrefined.
So let's try to fix that: You can pick a different "favorite" god whenever you choose. However, in order to prove your loyalty and receive their blessing, you must go on some sort of quest related to the god in question (i.e. Defeating a powerful Lich in the name of Arkay). You'd then have access to that higher blessing permanently (though only one at a time) by praying at the main shrine where you received the quest (Mara's Temple in Riften for example). The major requirement here is that there would need to be more major shrines to the gods throughout Skyrim.
Alternatively, we could just get more "Agent of ______" quests like the ones we currently have for Mara and Dibella.