The same is true of mainstream browsers. Would you not bother testing in even a single browser just because there are too many options?

There are two goals only if you don't do the first one. It's like saying the two biggest goals in owning a knife: not stabbing people and staying out of prison.

In my experience, it's a lot LESS work. Fair or not, the people reviewing accessibility standards are likely not disabled, and the mere functioning of a website is enough to pass WCAG 2.0. It doesn't have to work well - all of the bits that make a website nice are at level AAA or are advisory, and the government's claim here is that Level A Sufficient would be enough, it just has to work.