Your endorsements are a part of your personal branding. HR may not look at them much today, but as you move into more specialized fields or technologies, they begin to represent and provide additional evidence of your focus. My top areas of recommendation are Python, Finance, and Statistics, in that order, and these recommendations are largely coming from people who know me and my focus and are qualified to vouch for them. As my reputation for those skills continues to grow, so will the count of recommendations for those skills, as well as the quality of the ones recommending me, and I do consider that to be of value.
For my part, I try to only recommend people for skills I could personally vouch for, and for the skills that I would be considered qualified to assess.
I'll cite the Signal to Noise ratio here, and I think two factors contribute to the signal:
- The first factor is the number of recommendations: 1 or 2
recommendations don't mean much. Once you get into the double digits
on a skill, that becomes a signal of ones' focus.
- The second factor is the quality of the ones making the
recommendations. If they're a leader in the field for which they're
recommending you, that really means something (for example, if Linus Torvalds recommended you for Linux, that would really send a signal). If they're your
cousin and you've not actually ever worked with them, then it's not a big deal (but it does say your cousin doesn't consider you a black sheep).
I predict that as LinkedIn continues to be a hub for social connection of professionals, these recommendations will gain more and more weight with HR. The weight they have for HR is in providing additional evidence of your focus and reputation. The effect, for now, is hard to quantify, but I think it's stronger than interests you may (or may not) have listed at the bottom of your resume.
A third, less tangible factor, is on the aggregate, these recommendations are a signal of your ability to build a professional network, a desirable skill for most lines of work. I don't think you're doing yourself any favors by deleting them out of hand, unless they confuse the message you're attempting to communicate about your focus.