Re: 2nd guessed was Re: Revised Checkpoints: WCAG(1.4/1.3) and UAAG(2.5)

Broadly stated, what is meant by "impact" in this context is the extent to
which failure to implement a checkpoint makes it difficult (or impossible)
for identifiable groups of users to access the content. For instance,
auditory presentations which are not accompanied by captions will be
inaccessible, in respect of their informative content, to a definable
class of potential users, hence the priority 1 status of the requirement
for captions.

The guidelines are concerned with those aspects of the content itself that
render it either accessible or inaccessible, and not the more general
reasons why a large proportion of the total human population can't access
the web, for example the lack of appropriate telecommunications
infrastructure in many areas, the often prohibitive cost of network
connections and computer hardware for lower income groups (which
constitute the bulk of humanity), lack of relevant education even at a
primary level, and so on.