Here is the glaring difference. BABIP. Gomez had .273, .330, and .286. Hicks .241 and .233.
Well, the glaring difference would actually be defense. Gomez rated very well at the time defensively, offsetting virtually all of his shortcomings with the bat to make him an average overall CF; Hicks looks to be an average glove at best so far, which makes him about replacement level (or worse).
Also, Gomez was significantly younger. Hicks debuted last spring at age 23 years (and 6 months). Before his 23rd birthday, Gomez already had a full MLB season of 77 OPS+ and 2.1 rWAR under his belt, plus his partial Mets season of similar stellar defense. Hicks also had 4 full years of full-season minor league ball, versus Gomez's 2.
Finally, low BABIP does not automatically equal bad luck -- it could just mean a lower AVG hitter. That Hicks' low BABIP is continuing into 2014 isn't a good sign.
Although I agree, too early to pull the plug, given the alternatives. If he doesn't get going by June, though, establishing himself in AAA might be the best way to salvage his career?