I believe that to be true as well. Most compaining I see and most comparisons I see, regardless of converter, involve no effort to make adjustments or match conversions. Most are done with converter defaults. ACR looks uncompetitive using defaults.
NX is known for good conversions for Nikon but it's Canon support is weak
It's slow and hard to use and that makes it inferior to other tools strictly from a workflow ease-of-use standpoint. It's not what our software produces with minimum effort that matters, it's what our software is capable of when we use it that does. Using different converters with substantially different human factors, then comparing them using defaults, is intellectually dishonest as well as totally uninteresting yet that's all you ever see. If someone is willing to go to the extra effort of using NX then why aren't they willing to learn how to use ACR?
If the figure of merit were how good a conversion you get for the amount of effort you invested, then Aperture/Lightroom would win consistently at least until you got into the higher levels of effort. If an individual wants to work that much harder then I think that's great, but that's the reason that ACR/Lightroom is more popular than NX. As long as people keep making their arguments with converter defaults, they will never get the point.
I just wish it were easier to get a converter to produce a baseline result with no "look" of any kind. This should be a basic capability of every converter yet it's remarkably hard. I don't see how anyone can judge converters without the ability to achieve some objectively comparable starting point. If you can't shoot a grayscale chart and get an honest, accurate conversion of it then the converter is trash. There are a lot of products with that problem.