I agree, and I get endorsed by people I know but who know nothing about my capability of that particular skill (because they've never seen it exercised in my relationship with them).
I can only surmise they endorse me because once you give an endorsement you're encouraged to endorse the endorser right back, and maybe they're hoping for endorsement.
In short, since I get unqualified endorsements from others, I don't put any stock in endorsements that others have. It was a nice idea, but they should really pull the service.
As such, endorsements seem to have very little credence, and I certainly wouldn't be swayed by any I saw in other's profiles.