Now that we're more than halfway through the year, I have to agree that Limited Time Magic was a pretty big-time fail on all levels.
There's been no apparent marketing of the promotion whatsoever to the vast majority of the parks' guests. We get Disney parks commercials on TV all the time, but they're all the generic "family vacation" ad -- I haven't seen a single one that even alludes to LTM, nor have I seen any banner ads on the internet either. What's worse, there's no hint of the promotion on the official Disney website for either WDW or DL. To the extent casual or "once in a lifetime" visitors might be intrigued by the promotion, you're not going to draw them in if they have no idea it even exists.
The only people who are likely to be aware of Limited Time Magic to any significant degree are relatively dedicated Disney fans. But, for the most part, the LTM offerings have been widely panned by the fan community as uninspired and less than compelling -- especially the events at WDW. To the extent some of the LTM offerings might be of interest -- like "Long Lost Friends" -- they're of such short duration, and announced on such relatively short notice, that it's extremely difficult for most non-local visitors to plan a vacation around them. (And, since LTM events aren't anywhere close to being equal in quality, there's little incentive to just visit "whenever" with the assurance that you'll likely appreciate whatever it is that's going on when you happen to be there.)
That leaves the local/AP fanbase, which has the greatest ability to patronize the parks for a LTM event even on short notice. But APers' tickets are essentially already paid for, and I doubt the additional revenue they bring in by buying a "limited time sundae" or T-shirt really justifies the cost of the promotion.
Certainly with regard to WDW, LTM has been a complete dud. At this point, I'm sure Disney would rather just stop coming up with new things and hope people forget there was ever a 2013 promotion in the first place...