One of the biggest reasons people who mod games (and there are thousands of people) use 3DS Max is because of the ".nif plugin". Blender use to support this import/ export, but for some reason they dropped it. My Question is.... Can someone PLEASE make a plugin to Import/Export .nif files for Blender. I guarantee Blender's user base would grow by over 10,000 people.
This seems to be a feature request, not a question about Blender.
You can't "guarantee" any "user base growth", nor is that a valid goal. There is no direct benefit in that for whoever would bother making such plugin.
You could either try hired development if you are interested enough to invest some money in it, or request that in a forum like Blender Artists.
Also a little google search yield this that may be of interest: