Is it a good idea to have a large footer containing many links?

In recent years, it's become quite a common design pattern to have a large footer on every page, containing a 'mini sitemap'.

For example:

This has supposed SEO benefits but would also seem to be a legitimate use of page estate. However, such footers contain many, many links, and I'm wondering if that's a hindrance to screen readers and/or keyboard users.

Any thoughts?