Many posts here demonstrate willful ignorance and entitlement in my opinion. A few posters have said they don’t understand boundaries and/or insist they are unnecessary. The internet is a wonderful thing, I think any poster could spend 10-15 minutes googling the role of boundaries in relationships and do a little reading. In reference to estrangement and the role boundaries may play in the dynamic, it could be useful to those struggling with being estranged to have a basic understanding of boundaries since they often seem to be a point of contention.
The example of unsolicited advice to me demonstrates an entitlement to having one’s thoughts and feelings catered to at the expense of other’s comfort. Why so much fuss about unsolicited advice? Why indeed, is there so much fuss about keeping one’s thought to yourself when asked? Just because you (and by “you” I don’t mean any poster in particular, but those who think they are entitled to offer advice and opinions regardless of how the other feels about it) don’t see the harm or annoyance in hearing unasked for advice doesn’t mean it can’t be harmful or annoying.
I think some people, likely those lacking in emotional maturity, take other people’s boundaries personally, especially if those boundaries require they change their behavior in any way. They may feel that being asked to change their behavior means they are bad and are doing bad things, and thus following the boundary would be an admission of guilt. This seems especially often when an adult child gives boundaries to a parent who still expects obedience (though they may say “respect” or “love” when they mean obedience.) Giving advice isn’t bad or wrong in and of itself, it becomes wrong when the request to stop is ignored. No one has the right to say or do whatever they want to another person. “You will not give advice to me about my children” is not controlling. “You will not give advice ever” is controlling. The boundary isn’t about how the other person functions in their own life or with other people, but how they function in the relationship with the other person. Very simple to comprehend, frankly.