This is so condescending. The reason I buy used is that the overwhelming majority of books are out of print and not available digitally. Which makes the vandalism especially egregious!
vandalism is destruction of someone else's property. that's not what is happening when someone chooses to write in a book that they own.
It was extremely common back in the 1500/1600s, when books were far more rare and valuable to write in them. Almost every copy of these truly old books has something written in them, often by multiple people as the owners changed. That's part of the history of the book.
Learn what words mean. That comment is not remotely condescending, and scribbling in one's own book (with no indication here that the owner intends to sell it) is not vandalism.
Oh, I recognize your name ... wrong about so many things.
From another one of your comments here:
> No, my argument is that it's totally obnoxious to lend or resell a book that you've written in
But the person who advocated for writing in one's books if desired said nothing about lending or reselling them ... YOU were the first person here, in your response to them, to whine about BUYING such books. Talk about obnoxious!
It's not vandalism. Calling it that is condescending.
You can buy unmarked used books. Just check. (And if you're buying online the state of the book is expected to be in the description.)