Pretty certain we all agree that anyone who buys a piece of gear, knowing full well that they are going to use it in some beneficial manner and then return it for a full refund - is a 100% AAA-Grade douche-bag.
It's a seedy part of retail, but almost inevitable. Doing so obviously has an adverse effect on the retailer which can have an adverse effect (cost) on the manufacturer in returns/repairs/restocking items at a sharply reduced margin. Some rationalize that both of these parties "have more than enough money" to absorb these expenses, but everything has a reaction and invariably the consumers are left to foot the bill in the end, usually in the form of price increases.
Beyond the self-defeating economics, the ethics of abusing return policies in a premeditated, systematic way is still slimy. I know of people who've done it, as well as YouTuber gear reviewers who do this very same practice. There's no way to avoid it since human nature is human nature, and sadly those of us who abide by the honest intentions of a return policy tend to suffer when policy privileges are changed or revoked because the added expense becomes too costly.
C'est la vie...