I want to ask everyone?
what do you think causes people to behave like that, namely always buying at high prices,? but when the price is cheap he doesn't want to?
Different traders have different strategies, and buying high is fine if you can sell it higher. For example in a bull market when new ATH keeps going higher, you'll be fine buying on previous ATH. Conversely, buying cheap can destroy you in a bear market where new ATL keeps going lower. Your previous ATL buy can be the new resistance or worse, the new ATH.
A very fine example of people getting rekt because buying low is when LUNA (now LUNC) collapsed. At that time, $1 seemed dirt cheap and yet the price went to $0.0001.