TBH Ov9 you would have that opinion as you have a surrogate child, a child through surrogacy.
If you had an egg donated to make your son do you know that the egg donor is ok, both mentally and physically? Does she remain fertile? Does she have reproductive cancer?
If you had a surrogate mother who you paid to grow and give birth to your child, is she ok, are you still in touch? Family member, friend or stranger? Uk or abroad? Is she ok, did she suffer any incontinence, birth injures or mental problems (I'm not sure she would tell you so that's maybe an unfair question, she might want to uphold the image of being generous and completely unaffected but might be in private counselling, if she can afford it).
Your boy might be a happy little person on a day to day basis but if he came from donor sperm or a donor egg he might one day fall in love with a half sibling and not be able to have a family because of the close relationship. However, he might be in a same-sex relationship and be all set up to have a family using a woman's body as he came into the world that way so has learnt that women, or some women, are there to provide a service.
Have you told him or will you tell him about the circumstances his birth?
You may think all the above is too personal, but your position on this is personal as you have personally benefited from surrogacy. You are entitled to your own opinion but your experience and the experience of the women involved in the birth of your child are not necessarily the experience of all women involved in surrogacy.
By comparison we do not legislate for the 'happy hookers', we legislate against sexual trafficking/slavery.
Being able to sell your reproductive system or your ability to procreate is not for you, or I as individuals, to decide but it is a fact that most countries have banned either commercial surrogacy or outlawed surrogacy entirely.
Pro surrogacy people, including the Law Commission, say the Uk law is outdated because people should be allowed to buy babies and why can't women use their wombs to make money. Personally I think the current and proposed laws in the Uk are way behind other countries. They have it right and we have it wrong.