Exactly - let the professionals do what they can. I am a designer and I could learn how to code a site in Rails or Python, or whatever, in a few weeks but the code would be a mess and the site wouldn't be optimized and I'd waste a ton of time figuring all that out later.
I'd rather pay someone who knows what they're doing and can do it right the first time.
I'd rather pay someone who knows what they're doing and can do it right the first time.