I've worked on basses even longer than I've played them, so I feel qualified to answer.
Because bass players are weirdos. Starting with me, mind you. We do things that defy all logic, yet define Cosmic Symmetry. The stickers (or what-have-you) are just cover for something deep-seated. Me, I use the heavy-duty rubber bands from a bunch of broccoli as a stress reliever... for my 5-pin cables. Now that's messed-up on any planet. I also invented chocolate Cool Whip in 1976. Nobody believes me, because my Mom destroyed the proof and docked my allowance for another bowl of Cool Whip and a can of Hershey's. She hollered a lot too. But I arrived at the idea independently. Just like the broccoli band cable stress relief. And two or three pretty slick bass parts I have come up with in a flash that nobody heard coming, but grinned when they realized what I just did to their boring little groove.
I had one customer who was determined the bridge on his Kay upright should be moved 2" closer to the fingerboard, and (get this) be turned on a slanted angle so that the crest of it was 'compensated' like his favorite guitar. I gave a detailed explanation for why this was structurally ill-advised if not impossible, then handed him a bill for repairing a collapsed top, and... watched as he moved it back where he wanted it, in my driveway. Stickers? I think dude needed one. But hey, I did my job. Maybe he had something there.
It's a great big world, and sometimes people do things that don't make any sense to us, or just think about things differently. If you watch them a while, you might make a Bazillion dollar$ on a delicious dessert topping before the Birdseye people get wind of it 20 years later.
*Agree with Adriaan; that one has the hallmarks of a Fernandes. Not enough detail to say for sure.
