I don't know which of the two is more correct:
- This site is not meant merely to determine the popularity of specific tools.
- This site is not merely meant to determine the popularity of specific tools.
Cant these be safely used interchangeably?
The first implies that the scope of your site is greater than simply determining the popularity of tools, and it could be construed as dismissing such a low goal as not worthy of consideration.
The second affirms that the site is meant to determine tool popularity, which may be a laudable goal in itself, but that the site then goes beyond that worthy expectation.
If determining the popularity of specific tools is an idea you wish to affirm, then go with the second. Otherwise go with the first.