I don't completely disagree.
My business website is shared in my signature. It's less of an ad, and more of a connection to who I am. It allows people to research me further, to understand who I am, and what makes me credible in this field. That said, my website is not really set up as an ecommerce site, so I'm not expecting to gain any value from promoting my website. In fact, it is rare that I ever profit from my involvement with this forum. Though, I have been a member of this community for 20 years, and consider myself a key contributor in the "Talk to a Mechanic" sub-forum.
That aside, I will acknowledge that the Olhausen logo in my signature is 100% an ad. I'm proud of my association with the brand. But, if it is bothersome, I am happy to remove it from my signature. Though, I will absolutely NOT remove my business website, for the reasoning mentioned above.