Absolutely right that technical people (and preferably nontechnical managers too) should have experience of support. Senior developers and designers and architects who have no support experience often cause more harm than good, and the same goes for those without support experience who think they can micro-manage developers, designers, architects, or support staff.

But when I was young, we didn't have helpdesks and everyone did support anyway - it was regarded as part of a developer's job to interact with customers, discuss their problems with them, and help them generally. I can remember (way back in the 60s) crawling around on the floor at a customer site, with my MD (I suppose that's CEO in USSpeak) crawling beside me, while we were trying to work out why some hardware was doing strange things. So I'm not convinced that it has to be a year in a spefically support role, it can be time in a job with not dedicated to support but with a high support content.