You can easily evaluate their quality
There are two or many possibilities, to mention some:
1. If they are profile links, for example, in a community site (like an education page) and you have never posted anything in that community site the OPR of that profiles is 0: no incoming links. Therefore they are never going to be indexed, because I seriously doubt that the site will be willing to include or their profile links in their sitemap. You can just try to force them index for the lols but I doubt it will be a major change in your sites
Also, there are those sites ultraspammed with 150 other comments with their links. Regardless of the OPR, the link juice to your site is going to be barely 0. Just for the lols. Most people just index these type of posts, because they theorically provide page rating, meaning that a single page, within a powerful domain (for example a 2.0 property) could have value for ranking other sites.
2. But if you are talking about a citation site, that has not been indexed, despite the fact that the OPR could be minimal (being your site listed in the page 150 in a directory index of 160 pages), citations are useful, specially for a Local SEO site for branding purposes, so yes, force the index.
