The problem with NMC is, instead of using NMC, other projects usually copy the idea (not that anything's wrong with that) and build their own custom version of decentralized DNS. One example is
ENS (Ethereum Name Service), I've also heard EOS was trying to do something similar. First-mover advantage doesn't always help.
That is completely true, and it was also the reason why I thought, some years ago, that NMC would be soon forgotten.
But until now, no competitor has really got any traction - at least in the DNS field, Namecoin is still the most used blockchain based DNS system (see
here). ENS has some advantages to NMC, like the "auction process", which leads to a dynamic fee for demains according to demand, while in NMC the registration has a static fee (I know there are plans to change that). But on the other hand, everything on the Ethereum blockchain suffers from pretty high transaction (gas) fees. EOS in my opinion isn't a competitor as it is not decentralized, at best it could be an OpenNIC competitor.
And yes, there is the risk that NMC never gets popular. Otherwise the price wouldn't be so low. That's why I wrote that NMC is a big chance for investors that are also coders.