Unless I misread, I don't believe I saw anything that implied that the poster was claiming that anyone with a modicum of smarts could contribute significantly to the study of elliptic curves as relates to Diophantine equations. That being said, there are a mind-boggling number of extremely specific sub-specialties in mathematics, each of which would demand a significant investment of time from even a very intelligent person to reach a deep understanding of the state of the art. The fact that only a handful of folks are sufficiently versed in a particular sub-specialty to evaluate a long, involved and presumably brilliant proof attempt that draws significantly upon the state of the art of that sub-specialty does not imply that only a handful of folks are sufficiently intelligent to evaluate the proof. This reminds me of the recent attempt on the P/NP problem by Vinay Deolalikar - plenty of extremely talented mathematicians watched from the sidelines because they did not have sufficient specialized knowledge to properly evaluate the proof; though, that did not imply that the proof was particularly brilliant or even correct (http://michaelnielsen.org/polymath1/index.php?title=Deolalik...).