Because it literally gets me nowhere so I don't give a fuck anymore. If a man thinks Im attractive what do I get from it? I don't need their sex. I can get off on my own and with porn. and if I do sleep with a man and attempt a relationship...most of the time it ends in them avoiding anything that even constitutes a relationship while keeping the sex going as long as they can. Believe otherwise gives them opportunity to emotionally manipulate me as long as possible to keep the sex going as long as possible. Then comes months of time lost focusing on this instead of things like investing, working on my home, my job, or my son. then there's lost time with my son due to courting them all to find out they were just prolonging the fucking period as long as possible while avoiding the relationship part. Not to mention most men don't work out or care about their bodies...so most of them Im probably not even going to want to have sex with. So given all this...why should I give a damn if someone finds me attractive? The only person that matters in that regard is me.

I really feel that I can love myself no matter what I look like because for me it's not about my looks whether Im a good person or not. Looks can help in situations such as getting a job, position, or talking your way in or out of a situation. There really is a world bias for attractive people. I workout now because its like I can feel my body and soul thank me for doing so. Its a way of loving myself and staying strong. I value strength in myself mentally and physical. For me its empowerment.

I also value all forms of art. Some people get facial piercings or visible tattoos of crazy things, etc that change their appearance. Cut their hair short or die it purple, blue, or green, etc. Someone might say...how can they stand to look like that? But to me that is their form of expressing themselves. some people have very colorful, deep personalities that make up for their plain appearance. etc

@Lauraleigh39 Thanks for the very detailed answer!
Yes when it gets right down to it it's primarily for myself I'm getting back to something resembling respectable condition, rather than borderline obese. The chances I'll find another companion at this point are vanishingly small. And being retired, I've no co-workers to impress. The people at stores and shops could care less. My therapist just quit her job so there's not even her...
Sex? My last companion was constantly pressuring me for it until she finally gave up. She was a rather attractive 83, but that was too much of an age difference for me. Like you, porn is preferable to getting stuck in a deadend relationship with all it's obligations and demands on my time, mental reserves, and emotional stability.
In fact I'm now a recluse and enjoying my solitude, as long as I have something to occupy my time, which at present is building a pond.
So appearance is only secondarily to satisfy the sensibilities of other mostly non-existent people. It's a personal pride, a desire to extend my longevity, and to aesthetically please myself. Even if no one else cares, I certainly do!
As for people with purple hair and nose rings, their ideas of attractiveness are their own.