"Frowned upon" implies that someone ELSE disapproves, and that it matters.
I don't "frown upon" BB King for not knowing how to read music.
If Larry Graham couldn't read (I don't know) I wouldn't frown upon him, either.
If you're consistently landing gigs with the top musicians in the world, are creating a style that others try to emulate, or are producing music that is loved by and touches millions of people, in general you won't be "frowned upon" for what you lack. But most of us don't fit into any of those categories.
But a better question is - will it make you a better player? Will it help you get better gigs, play more styles of music, and allow you to work confidently in more situations and with better musicians?
And the answer to that is a resounding yes.
As far as being a visual learner - get some basic books on reading. You can start with Mel Bay. Once you know the notes (and it's not that difficult), get "Essential Sight Reading Studies for Electric Bass".
The best advice I got, when I decided that I wanted to learn to read, was "read 8 bars per day, every day". It's like pushups - if you do them regularly, you'll get stronger. If you just talk about wanting to get stronger, or about if you should get stronger... well, not much happens.
As far as theory - it's not that hard, really. PM me if you want - I have some very simple approaches to understanding Western music theory, but they're not written out. Or grab a book.
One other question that I'll ask in Anthony's place - do you really know the notes on your bass? (I've worked with Ant long enough to know - he'll ask.

)
How long does it take you to finger every Eb on your bass? Are you sure that's all of them?
Music is a journey, not a destination. Enjoy the ride, and learn while you're on it.