People are the reason why there's lag in the first place.
Nexon doesn't like lag but what more can they do? Investing into better servers would take money and if people LOST THE HYPE AND QUIT, ALL THAT MONEY WOULD HAVE BEEN WASTED.
That's probably the reason why Nexon isn't making any rash decisions.
People have quit in the past after the hype is over. When there is new hype, they come back then they leave. It's the same process that has been happening for years now.
So if you want the lag to be fixed immediately, don't expect Nexon to fix it anytime soon unless the hype is over.