Are availability and anti-scraping mutually exclusive?

Likely. Availability depends on tools that parse the underlying code. For example, the table

"summary" attribute or the more general "alt" attribute on a tag img

. In addition, these tools can interpret code in ways that may not be as straightforward as this one.

Thus, if the site is accessible, it is somewhat the same as saying that the underlying code is easy to handle. And therefore, if it is processed, it can be easily cleaned up.

So, yes, you could say that this is an oxymoron.