Just Because Someone Else is Doing It Doesn't Mean It Is Right
There is an assumption many people will make, in any number of situations. If someone before them has done something a particular way, then they feel it is okay to duplicate it. They give no thought to whether or not the first person who did this thing did it within the confines of the rules or regulations.
Home Owner's Associations are great examples. As a Top Bristow Real Estate Agent, I'll be out showing a home and get a question from a buyer, "Does the HOA allow a black and white deck?" They'll want to go with some nautical theme where they have vinyl white railings and the appearance of black wrought iron spindles on the railings. They next thing they do is look up and down the back yards. "Oh. I think they must. That house there has one."
It could be a privacy fence, above ground pool, shed, play house, garden or any other number of items you picture in your outdoor space. Seeing whatever it is you want one someone else's property in the same neighborhood is not enough to assume you have the all clear.
No buyer really ever wants to read through the HOA documents they get and find out what is and what is not acceptable in the neighborhood. Looking at what other home owners have done is certainly easier. However, as borings as those HOA covenants can be, if you have something in particular in mind, you better read through those documents and figure out if what you want is allowed by the HOA rules and regs up front. That's what the whole document review period is for.
Better to know what you can and can't do for a fact, than follow the lead of someone who may not have a clue.