I see 3 major problems with NXT to become a major payment network.
1> Its distribution to 73 big stakeholders through an IPO.
It will be difficult to justify, a lot of people find this outrageous.
It's already difficult for Bitcoin (62% of survey respondents think bitcoin is a scam).
I cannot believe that is still an issue.
2> POS system.
Miners are important parameters in the ecosystem and marketing.
Investors are important to miners and miners are important to investors.
Both Bitcoin and Litecoin had a huge amount of miners on-board before anyone started using it in markets.
So what?
3> JAVA
Probably the worst.
Java is considered bad by many developers. Java is trying to install a shitty toolbar every time you install it or update and it is so insecure.
No open source programmer would ever use it.
Many people don't like Java and they will never add it (I believe it's why mcxnow never added it because it's Java client).
C/C++ are languages of choice of the industry. A C++ client should be developped to become something professional and credible.
Feel free to re-program the server in C++, C, Assembler, Python, Ruby. And feel free to program clients in ObjectivC for iOS, Java for Android, for WinRT in JS+HTML+CSS or C#+YAML.
I do not see why the programming language has anything to do with something language-agnostic as the
Nxt Protocol. It is a protocol; the programming language is completely irrelevant.