I don't have a photography degree, but I do have a BFA from the School of Visual Arts (SVA) in painting and sculpture. Photography was part of our curriculum and I learned a lot in the classes.
In fact, many of the disciplines we now work on digitally in photoshop have their roots in traditional darkroom techniques. The tools and filters at times are even named after the original techniques.
Not to mention the art of photography that is outside of the technique itself that is way more important. Composition, color theory, creative thinking and problem solving to name a few.
Could you learn all of that on your own? Possibly - but then again you could learn any discipline on your own. It might take you a lifetime to learn what you could learn in 4 years of a BFA photography program.
If you are just looking for continuing education classes, most community colleges, universities, and art colleges do offer classes. And like someone stated earlier, you will have access to equipment that you wouldn't normally be exposed to.
Hope that helps.
I also went to SVA and got a BFA majoring in illustration. Never turned on a computer or shot a frame of film (even though I took a darkroom class) in 4 years of school. Now I am a professional graphic designer and love photography above all other forms of art.
The point is, art is art. It's all visual communication. Don't get so focused on the current tools you are using. The concepts of form, composition, color theory, etc. transfer to different mediums.
Since I have that art foundation, for me, learning a program or a new "system" is the easy part. Anyone can master a piece of technology.