Why are products not included in the Export Product List utility?

The Export Product List only includes products that are marked as Available on Web.

When the Export Product List tool was added to Acctivate, it's entire reason for existence to was help webstore uses quickly obtain a list of products that appear on their store so that they could import them into the site.  Because of this, the utility only exports products that have the "Available on Web" option checked.

AvailableOnWeb

If a full list of products is needed, you can instead export a relevant report to Excel or use a database query from Excel itself.  Check out this article to see how to create one.