Grammatically challenged

I'm not sure why stuff like this bothers me as much as it does. After all, I'm not sure how relevant a phenomenal command of the English language is when a runaway sewage pipe is in the midst of turning your beautifully finished basement into the second coming of the East River. If my plumber manages to stop the carnage, I'm perfectly willing to ignore his/her literacy skills.

Plumbers plumb, grammar wizards do their grammar-wizardry thing, and the two core comptetencies don't necessarily need to overlap. Still, things like this raise my blood pressure. You?