> I donbt know what about XSLT does not feel declarative.

I think it's primarily because it chose to use imperative verbs in its syntax:
apply-templates, call-template, select, choose, iterate, sort, group-by.

And I think that choice was probably made (perhaps subconsciously) in order to
make it feel more familiar to people who are used to procedural languages.

Michael Kay
Saxonica