That's the crux of the matter for me. The Sportsman should be an absolute goldmine on match-days, but due to the lousy service, most people who go there don't get the chance to spend as much as they'd like to, due to it being five deep at the bar, and many more potential customers won't go near the place for the same reason.
The food as well as the table waiting is some of the worst I have ever encountered. I tried it out for some post-work pre-match food one evening a few years back. Utter rubbish.