Replace the support for Views with a more generic support for Drupal pages

views without a path associated would not get any meta tags

Views that don't have a path are more probably used to create other views, or pages that embed the view inside them. In that case, trying to assign meta tags to such views would probably cause some problems.

Meta Tags by Path doesn't actually work with Meta tags version 6.x-1.x-dev, nor 6.x-2.x-dev.
It doesn't work because it's using two functions that are thought to be used only from Meta tags, and that have been recently changed. In PHP 4 there isn't the concept of private functions, but those functions are in someway marked as private by adding an underscore character as first character of the function name.

Then why not just fix Mata Tags by Path module rather than create something duplicate and less flexible?

To fix Meta Tags by Path, you would create duplicate code in that module, which is relying on a private function that it should not call.
I don't see how Meta tags would be less flexible when it would do the same thing done by another module.

Anyway, if Meta Tags by Path is not working with the latest version 6.x-1.x-dev of Meta tags is a different issue than the task report I opened here, which is about abandoning the specific support for Views in favor of a more generic support to pages that don't show the node content, a taxonomy term page, or a user profile page.

This task has been replaced with a more generic support for conditions, or rules; see #236833: Add more settings pages for the global meta tags for more details.