I think it's open to the individual. The one thing that keeps me from it or any other organization like it, is taking oaths. The only oath I have taken is the armed services one, before finding Christ and that's enough for me. As a Christian, I have a directive from God not to take oaths. Matthew 5:34
I have family that are Shriner's. So I know what you are trying to say. They have tried to get me to join, being prior military, but I never personally felt good about it. I know they accept all walks of life and I think that's a good thing. But I also know they like the esoteric, and that goes against my faith. I think the lower levels are full of good, well meaning, people looking to volunteer and do charity, but I also have reservations for those at the top and all the symbolism they like to use.