I think you made the point beautifully when you said "can get the basics down in a few weeks to a month". The key word here is "basics". A professional level of skill goes beyond basics. As a web designer, one can get the basics down of CSS, for example in just a day's workshop at a conference. That said, to be of any real value as a professional, you really need more insight than what a basic understanding gives you.

As for your comment about wanting back-end people refusing to do front-end work - actually, I myself do not have a problem with this. I believe people should do what motivates them at work and not get strong armed into doing things that fall outside of their professional interests. There is a limit to this of course, but in this case, there are definitely front-end people who will do the job better and take it as their career passion.