Most of the comments here seem to assume buying stars is about making personal profiles more attractive to hiring.

I doubt that's the motivation here. I think this is about projects themselves wanting a high star count in order to attract users, customers and investors.

This. I've seen a couple open core startups that are less than a year old with thousands of stars on their repositories, so I decided to have a look at some of these profiles who starred the project. Most of them have weird usernames that resemble spam accounts, almost all of them cannot be pointed to some other profile on a different platform (Twitter, LinkedIn, HN etc.).

Another giveaway is the ratio of stars to watchers / forks. I remember one project with thousands of stars but only 10 users "watching" it. They went on to raise a sizable seed round too.

> Another giveaway is the ratio of stars to watchers / forks. I remember one project with thousands of stars but only 10 users "watching" it. They went on to raise a sizable seed round too.

Not necessarily indicative of foul play. I have two projects like this (https://github.com/smacke/ffsubsync and https://github.com/ipyflow/ipyflow) and I attribute it to not having great developer documentation.