My guess is most muscular guys like other muscular guys. It isn't a prejudice, it is a preference. To get muscular, you have to put in a lot of hard work routinely for years, learn about food and supplements, and sacrifice time and money and pizza all to achieve a certain look. As you go through the process, you become more and more aware of the ideal body and fine tune your efforts in the gym to get the look. So that is something you appreciate and have earned the right to the preference. I'm sure there are some muscled guys that like slim guys, like the difference, just as there probably are some who like younger, older, fatter, etc. Don't wait for someone who's put in all the time and effort to give you instruction. That is looking for a free trainer. Working out is an individual thing. Why not find another guy you like that has similar interest in shaping up and do it together? Or start doing it alone. I guarantee you'll have a better chance of meeting a fit guy if you're in the gym working hard just as he is. But you do have to be working hard.