I really don't think that is a hard fast rule mate. Not one bit. Particularly with guitar the opposite seems to be true. All the greats are ear players. It's not dependant on theory learning at all but rather dedication to what they do.
I stick by what I said. You can play by ear and become a Clapton or a Beck. You can get trained and become a Malmsteen. May be a fast excellent guitarist but couldn't write a song to save his life. You see the same malaise with Satriani and Vai too. A complete inability to throw down a handfull of chords and make em work to something that people want to hear.
Who is the better musician in that instance. The Chuck Berry's, who everyone can enjoy. Or Vai/Malsteen/Satriani types that only get a audience from certain muso's?
Which one is the better entertainer, the most heard?

BTW I threw Berry in there because he is classicaly trained. Yet is a prime example of a terrible guitarist. Out of tune, out of time. But relied on a great ear to write his songs. He certainly didn't get Roll over Beethoven from studying Beethoven.

This is why these sort of topics are very interesting. I never said it was a hard fast rule. The thing is everybody believes in what they believe and it is always going to come into conflict with others. My real opinion is let music be music and however you learn good for you. That is all I meant by what I said. The thing is though people cannot simply say what they want to say without someone with a more lax definition coming in to talk. My opinion is there is no correct response. Music is so abstract that there is no proper "how to" for any instrument. If you love playing guitar like I do however you want your guitar journey to go that is up to you; ultimately, this is what I was trying to say.

BTW Playalot.
No conflict from these parts. Maybe a very minor disagreement on certain trivialities, but thats about it. Please don't think that I am attacking you.

It is all important. The more you know and understand the better you can communicate and formulate your ideas. It is not a choice you make between having a good ear or reading and understanding music. You need both. You have your whole life to do this. So, what is important now is up to you.

For me, I am interested in why certain intervals sound good so I want to map it out with theory.

No I don't quit, ever. Especialy when I know I'm right.

Also looking at musical history you'll find that theory is entirely based on hearing.

Matt the truth of the matter is that modern music theory is woefully inadequate for that task.
Take a look and see for yourself why.

http://www.lucytune.com/new_to_lt/pitch_01.html

Allow myself to quote myself,

I would like to restate the above. I need to learn it all. Part of my personality is to define and measure the things that interest me. It helps me to remember things when I know how they work. I have seen a lot of players that smoke me that don't know how to read music. I think the end result depends on the person and how well they know themselves, as far as, maximizing potential. There are some commonalities that we share in learning and progressing but, no one can do it for you. Decide what you think is important about music and invest in that. For me, I am interested in why certain intervals sound good so I want to map it out with theory. Also, I am in it for myself, I don't plan on releasing an album anytime so I'm really only concerned if I like it (and sometimes my wife). Ok, back to my mountain top.

I only became a decent weekend warrior and fullfilled my fantasies after I buckled down and really studied the basics of music theory and learned to sight read musical notation. I still can't read and play on the fly. It helps when I think I've got something figured out by ear and then look at it and see I've been playing it right or most often wrong.