Yorick' Q and interactions with structures

Is there any particular reason as to why Yorick's Q isn't consumed against structures? Is it specifically to stop constant sheen procs against structures due to ghouls and his Maiden already filling up a hefty part of his push potential?

I mean it just feels so awkward at times where I just generally spam between my E and Q getting as many sheen procs as possible but it just seems to be such a strange way to hamper push potential when it's part of his niche.