While Nick Gonzales shouldn't be written off by any means, there are a few things that need to be clarified:
1) His lofty collegiate stats are largely seen as completely irrelevant in any scouting sense. He plays in a comical hitters' environment in a non-elite conference. The Cape-Cod performance proves that he can indeed hit at a potentially elite level, but no one really cares that he hit .450 or whatever HR pace he was on during normal collegiate play.
2) He is only potentially in play at #2 on an under-slot sense. This does not mean that anyone actually considers him to be the 2nd best player in the draft.
3) There needs to be some clarification on the comparison to Hiura: while Gonzalez is expected to be selected higher than where Hiura went, he is actually projected to be a lesser version of Hiura due to the fact that he isn't believed to have the power upside of Hiura. Remember that Hiura's draft stock was largely affected by the fact that he was DH'ing and recovering from TJ surgery in his draft year. He wasn't playing defense at all. I think that Gonzales is generally more athletic and thus has higher defensive upside than Hiura, but he is NOT seen as a "superior" version of Hiura. Both guys are bat-first players, and in this sense Gonzales is expected to be a lesser version of Hiura.
Keep in mind that New Mexico State played a 3-game series against Texas A&M in Texas - and apart from Asa Lacy completely dominating him in this matchup (one scout said that Lacy made him look like a little kid) he was largely invisible in the series overall. He also went hitless in a game against Arizona State. These are obviously small samples, but its an important analysis to consider any time you see a player who is putting up video-game numbers against garbage competition. Nick Gonzales' upside will ultimately depend on how much power he ends up hitting for, which I'm sure will be the biggest point of contention in draft rooms. It is possible that his elite bat-to-ball skills translate to more power than people expect; if this is the case then he would be a very good selection at #5. However, if he only hits for average power...I'm just just not sold on that package out of an average second baseman, regardless of his hit tool.