I look at this from the standpoint of grade and quality. Grade is the indication of the level of refinement and quality is the ability to consistently meet that grade.
Nissan has targeted the medium to lower-high grade segment and in my opinion dominates it and builds quality products. The fact that they continue to be the first to market products such as an everyday supercar (GT-R), a high performance sports car for under $30K and a fully electric car tells you that they have their $hit together in most if not all business aspects. They continue to go to market 2-3 years ahead of the competition with innovative and game changing products. That is a tell tale sign of a very healthy company.
The Hyundais and Kias of the world are working their way up the grade ladder but from what I have seen do not yet have the quality aspect down just yet. Let's see how the Elantras and Sonatas are holding up 5 years from now. I hope they all improve as it will force Nissan to raise their game even more.