I don't think this is "spammy" nor "unnatural". There are important persons in our life that are worth keeping contact with for the sake of keeping contact with.

If you create this list and it's only filled with people that could be helpful to you in the future (agents?). Maybe it's time to recall that we the people are ends rather than means to themselves.

Second, Mental memory is lossy. Sometimes you move for a while to another city. It's easy to get distracted and forget to keep in touch with the people you love.