This is my opinion so I have no "hard-data" to backup, I think most (if not all) Nim users are people who already have experience with other languages. People will gravitate to something that have most lib, most tutorial, most documentation, and most easiest for solving their real-life problems (e.g. Python which have sheer amount of libs and documentation/tutorial)
This also my opinion, I think another reason why people solving problems in Project Euler (other than recreation ofc) is to get familiar with syntaxes. Means, few people solving problem in Project Euler using Nim shouldn't something that alarming, it's just Nim syntax is so easy that they can pick it up easily. (Again, this is my opinion).
