Krono have functioned exactly as they were intended and been very successful and have been for the nearly 5 years that they've been in game. When they were first introduced I was staunchly opposed to them just as I opposed free to play when that was introduced. I've changed my mind because they've kept the game going and healthy and it's doubtful that there'd be TLP servers if not for Krono. So overall a net positive and they are no more likely to be traded illicitly than any other in game items.
Real talk: If your monthly entertainment budget can't float $15, your time would be better spent not playing video games to start with.
I remember years ago like pre eq2 people always advertising in game chats buy plat $5.00 USD will get you 5kp lol