My theory on GAS and hopefully I'll be more succinct than Scotty D...
My handwriting is ok. It's legible and some people think it's pretty i.e. I get asked to write stuff when I'm in groups at work, on the white board, on big sheets of paper. Gimme a bic pen and my writing can be understood but given the choice I'd buy myself some Papermate 'Atlantis' pens as they're a bit more expensive but still very affordable, they feel good to me (and I can easily identify one if my colleagues nick it). If I'm feeling flush I might buy a Lamy pen, their Scribble and Dialog are personal favourites, as I quite like their style and design.
My point....
I've played Squires, Epiphones, USA Fenders, Musician basses etc and I'm fortunate to own a really nice bass at the minute. Do I sound any better or worse on those different basses? Perhaps? Yeah some feel better, are better made and will inherently be 'better'..... but I still sound like me on them.
In the same way a pen might have a moderate influence on my hand writing it's always gonna be my handwriting, the same way a bass will dictate some small changes to how I play/sound. Gimme a crayon and my writing will look clumsy for sure but once we hit a certain standard its calligraphy lessons that will make the difference not a quill and pot of ink or a Mont Blanc. Same with bass, concentrate on what you play and becoming a better player and the other stuff will come.
Disagree if you like but those are some fine pens