I could easily see the utility of being able to sharpen your own blades if you utilize a lot of reclaimed or "dirty" lumber. Also, I didn't see if it could, but being able to sharpen 7-1/4" circular saw blades would give that tool a bit more utility. Doing remodeling work, you could easily burn through $50 worth of 7-1/4" blades doing demolition work. Stuff like cutting asphalt roofing, or just hitting nails, rocks and grit can ruin even a brand new blade. Assuming you don't actually knock teeth off your blade with what you hit, it could be used to restore it back to service a few times.

I have a couple dulled Avanti Pro 10" 60T crosscut blades sitting around, I bought them at home depot on a sale, it was two blades for $24.99 or $29.99 or something. Doesn't quite make sense to have them sharpened (because of the teeth count) but I didn't really want to just toss them either.