The use case for this functionality is someone new comes to the site wants to learn about OpenACS. One of the things they will want to do is look at sites that are built on OpenACS.
It looks like OpenACS will shortly become a leader in accessibility! Thus we should certainly expect that people who need accessible web sites will be coming to OpenACS.org to find out about what they could accomplish with OpenACS. Having the directory of sites area inaccessible would be very bad. Perhaps we could meet with Miguel and talk about how we can be sure it is accessible or an accessible alternative is available.
Also, are there questions we could ask site owners/developers while they are registering their site that would be helpful/interesting to potential new users of OpenACS who are interested in accessibility? What can we ask that will help potential users interested in accessibility issues learn about and connect with existing sites and users also interested in accessibility issues?