There is a lot that goes into ranking a site and generally the more authoritative the site, the more it can get away with. A few backlinks like the one you posted wouldn't even hurt a normal site. On top of that, you don't know if these companies have these links disavowed in Webmaster Tools. If you have SEMrush, check their rankings over time and estimated site traffic for anything suspicious. You can also check Ahrefs for anything unnatural in their incoming links graph such as spikes. Even with this you're only looking at a portion of the data and missing many link types that most backlink checkers don't show such as NAP listings or social/web 2.0 links which rarely show up in OSE or Ahrefs.
Look into them but don't dwell on what a few are doing. If you want a better picture, look at some of the sites from other major cities as well and look at what everyone in your industry is doing to find ideas how to improve, without wasting energy complaining that someone is getting away with something.