Counterpoint:

Events aren't about rewarding you for staying subscribed, they're an extra incentive to stay subscribed. If you think the value of an event-exclusive item is justified by staying subscribed when you might otherwise not, by all means justify putting money into the game however you want. However, you can't possibly give me a reasonable explanation as to how someone else being able to spend money on the game to obtain a single item that you got effectively for free with generally little effort (that has no game play advantage) is anything other than good for the game and its continued success.

Furthermore, what would you tell any new players that would really like X event-exclusive item? Too bad?