Clothing is the most universal & oldest manner in which most people express themselves. To tie your company to your identity so explicitly is unhealthy, and swag signals that to everyone within eyesight. My disdain most applies to every fashion with blocky company branding.
There is a way to do swag tastefully. I love MSFT's patent cubes and laptop stickers, it stays limited to professional life. Useful electronic gifts (tablets, headphones) are great, because the branding is an organic part of the product you buy. Even clothing can work, if the branding is undetectable. (Themed around tech, but not the company).
No, don't give me a 300$ Patagonia jacket or hiking bag with massive unremovable branding. I want to go climb my target mountain on it, and I do not want 'company name' plastered over some of my fondest memories. NO ONE has ever looked at a person wearing 'company brand' t-shirt and thought : "Gee, they must be smart, they work for big-name company'. This is further exacerbated by the fact that big name FANG+ companies are effectively in the business of advertisement and attention exploitation.
As long as tech people keep wearing terribly fitted company swag for everyday activities, I can't sympathize with their complains about tech careers perceived negatively in the dating market. We brought this upon ourselves.