Variants sell comic books and make Marvel and LCS' money. A lot of people describe them in pejorative terms like "gimmick" or "money grab," but they have been a consistent part of this industry for 20 years. They are completely optional and do nothing to devalue the non-variant editions. They get people excited about comics, allow artists to showcase different work, and generate significant activity in comic book collecting. The only people that have a legitimate complaint about variants are those trying to collect entire runs, and are prevented from doing so by super rare variants that are difficult to obtain. Publishers create variants because it allows them to increase their profits by selling more books with limited overhead. And people keep buying them and snatching them up, so as a business that wants to make a profit, it makes sense that publishers would use variants to try to increase sales.