Yes, it is
Now, for the "why:"
When I made this, there were NO multi-receptacle 'construction duty' extension cords. Jobsite GFI's were hard to find, and quite expensive. It seemed that the only "acceptable" devices were the 'spider boxes,' and those were usually fitted with twist-lock receptacles.
I also wanted an orderly way to carry and store the extension cord.
Even today, a decade after I made this thing, comparable items sold in the "box stores" lack GFI protection, and use smaller cord. The reel holds 90 ft. of #12 SJTEOW cord. It also snaps atop a 5 gal bucket
Things are improving, I did recently see a 'spider box' that, while still pricey, at least was outfitted with ordinary receptacles.
DeWalt has also come out with a 3-receptacle gadget that also has a built in light and two battery chargers.
I only regret that it has but four receptacles. Even the most basic job uses three: battery charger, light, and one tool.
