There are all kinds of love, and all kinds of situations. There is the unconditional love, which has no conditions. I like the Summerhill School method, but of course, I don't have any kids.
In this, you are free to do whatever as long as your actions don't harm anyone.
NOW, there are rules for different reasons. Some are that the person wants to be proud of their kid because they want that individual to become molded into what they want. To some degree this is based on expectations and beliefs. For example, "normal people clean their toilet every day", or "normal people like sports, therefore my child will like sports." Then, like always, the parent develops hurt feelings because the child makes them look bad. Hurt feelings develop because there is a difference between expectations and reality. Thus, because they are angry, they hurt.
So another example, you tell your parents you have homosexual feelings, let's say. They start crying, and "You pierced me through the heart." Well, you see, the gay person didn't do anything. The parent's expectations created this pain. They expect grandchildren. They have a vision.
Others are shunned for reasons of faith, like leaving a particular faith, JW, Mormonism or whatever.
In those cases (perhaps all cases) the conditions are set not out of benefit or love, but because the parents have an idea of what you should be firmly planted in their mind, and they are going to pound it into the child.
Now, other conditions are set because they want the child to survive and do well on his own. This is a different case, and it depends on how the parents believe. This teaches things like work ethic and how to balance a check book.
In addition, cultural things (like keeping things clean), could be taught without using violence or the word "normal".
Liking sports: Somewhat trivial
Homosexuality: Acceptable, but may need support...not rejection.
Abortion: Be understanding, present options without bias. I'm pro-choice, but I don't believe it's as simple as removing a wart or something...at least what I heard. It's like having to choose between difficult choices, both choices having emotional consequences.
There are so many other things. I wished my parents talked about things like finances or credit. I wish I'd gotten a job in high school rather than becoming salutatorian. So if I had kids, I'd wish to teach the things I wish I knew at that age.