File this under “no really, your teachers aren’t just trying to be mean”:
If you’re working with a startup, odds are you’re wearing a half-dozen hats and doing too much with too little. Often, this means that founders are writing their own website copy, press releases and blog posts. Too often, that results in grammatical errors that reflect poorly on the startup.
Developers may not care, but other folks do.
12 Deadly Grammatical Errors Startups Must Avoid from Joe Brockmeier at ReadWriteStart.