As with CSS, my first real contact with accessibility came with my job at Salford. Although I was peripherally aware of the concept, and had previously heard mentions of the WCAG (Web Content Accessibility Guidelines), it was never something I thought I needed to concern myself with. However, researching some of the legal requirements involving educational websites in the UK, I inevitably came across SENDA (Special Educational Needs and Disabilities Act) and the wider DDA (Disabilities Discrimination Act). To summarise very broadly, the DDA demands, among other things, that the provision of goods and services should be (within reason) accessible to anybody. In its initial state, the DDA did only cover businesses and government bodies, making a special exception for educational establishments. SENDA, which effectively became part IV of the DDA, removed this special status, bringing education back under the general provisions of the main DDA.
Although the Act itself does not directly mention web sites, the 'Code of Practice - Rights of Access Goods, Facilities, Services and premises' does, and it is understood that therefore all government, education and business sites need to make 'reasonable adjustments' to ensure a basic level of accessibility.
So, having started my position as web editor at the University of Salford and realising the legal requirement imposed by SENDA/DDA, I began delving deeper into the subject of accessibility. What I found was that, even among 'seasoned' web managers in the UK education sector and beyond, there was a lot of ignorance and confusion - coupled with misinformed management concerned with 'Bobby validation' as the be all and end all.
This sorry state of affairs, combined with the fact that, deep down, I feel that accessibility is simply the ethically/morally right thing to do, led me to explore this subject further. I find it fascinating that even though in recent years more and more sites, books and even conferences have been devoted to accessibility, there are still many grey areas once you move beyond the basics, where even experts can furiously disagree. It's not all cut and dry, and in many instances one has to take a pragmatic approach, weighing up how things should be done (according to things like W3C specifications or even common sense) against how they work in practice (in light of flaky browser or assistive technology support, for instance).