As Jeeqbit says, it's less an issue of "spaghetti code" itself as it is a situation where "spaghetti code" is just sort of a catch all for all of the technical limitations imposed by a decade of continued development. It's also important to remember that the basic structure of the game was built to run on a PS3, with all of the special issues that brought to the table. FF14 was rebuilt from the ashes of 1.0 in a rush and has had continued focused, ongoing development ever since. It also was never built to be as easily expansive and scalable as some other games.

So, no, "spaghetti code" is not an issue any more in the specific sense that some people use it in. But the concept of it is still very much a continuing drag on the game's development. If you think it's just an excuse made up by someone you clearly have no concept of how game development works... and you don't need to be a programmer or game developer to get that.