The all in one designer
Timing is another issue. At DAVE Networks where I spent three years designing social sites for Hollywood studios, I had a development team behind me so I could focus all my time on meeting the clients goal with the design. Rather than skimping it to meet deadlines where I would’ve had to if coding everything was included in my workload. Developers spend all their time researching and learning new and better ways to code, designers do the same from their side.
With design alone I have spent a lot of years learning Photoshop, Illustrator, Flash, Dreamweaver, Premiere, After Effects, HTML / CSS. Even Sonar and Sound Forge for music and audio editing and composition. I’ve dabbled with Poser, Swift 3D, InDesign, Quark and plenty of other programs. From a design point I can offer companies a lot of skills but I wouldn’t want to dampen those skills focusing my efforts with programming.
Asking one person to do both is only hurting the company by not giving the time needed to really please the client. Just my opinion anyway.