When it comes to the reasons for the initial bashing - there were many.
The main reason IMHO is the long time between the generations. Active members on prime were NA1/NA2-fans and I believe many expected a new generation like the first one - with everything dialed up. Even if Honda (Acura) have been vocal from start that NSX means new tech, fans still expected a Lotus Exige V6 with Japanese engineering and a Honda (Acura) badge. They plainly didn't like the new hybrid solution, with it's added complexity and weight.
It wasn't better that the price tag was a little higher than expected.
Another culprit was the 'long' time-to-market. Honda/Acura did mess up the marketing - it felt like it took ages from the first concept in January 2012. Then the production version was out-triumphed by the Ford GT 2015. But in reality Honda/Acura was working really fast, they even managed to re-design the main structure when they decided to change the engine layout from transversal to longitudinal.
On top of that Acura released the prototypes too early in Fall 2015 - and the rags wrote about the poor impression they got.
If Chris Harris wouldn't have driven and given his view - "They must have driven another car" - I might not have bought my NC1. I did, and I'm so glad I did. Four years later I'm still in love with it
Another point was also due to the release time - it was targeted against Ferrari 458 etc - but when it was released Ferrari 488 was the new kid on the block, and the 488 was a huge step in performance with its added turbocharger. For the Internet jockeys this was equal to a failure for the NC1 - and they didn't miss any opportunity to be very vocal about it. Fact is that professional race car drivers typically was a little faster with the 488, the 570 or the other contenders. Another fact is that many professional race car drivers drove the NC1 as it was a regular mid-engine supercar - as with the Nissan GT-R (which Porsche said the times was impossible) - it takes a special kind of skill to exploit AWD power (which works different in each car). Another take is that for non-race car drivers, they are IMHO probably faster in the NC1 than the 488.
The list goes on.
In any case it had a rough start - but I'm glad that it start to get more and more appraisal after a few years.