This actually doesn't surprise me at all but for some reason it is still in the news. Kaepernick is beyond his prime since leading the 49ers to the Super Bowl in 2012, their first in 8 years. The following year he lead the Niners to the NFC championship game... and from that point forward he was a non-issue until being released in 2017 and not being picked up by any other team.
Of course this is not what Colin is most famous for. What he is most famous for is likely a major reason why no team is interested in picking him up. In his last season with the 49'ers he stirred up controversy for refusing to stand for the National Anthem. Paying homage to the flag, whether you believe in it or not, has been a tradition in the NFL for, well, forever.
For many, this was a non-issue, but for others it sparked a massive backlash and NFL actually started to see decreased viewing numbers and decreased attendance as the more patriotic members of their fanbase started to boycott the NFL entirely. This was due largely to the fact that Kaepernick's display was picked up by other members of other teams.
When Colin became a free agent, no team wanted to touch him due at least in part to the potential negativity that was associated with him. I, however, felt as though they perhaps didn't want him because he already wasn't playing a great deal when he was released and when he did play, he was, in my opinion, average at best.
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He filed suit against the NFL claiming there was a conspiracy against him
So you've got a player that is going to attract negative attention from your own fans and the rest of the nation surrounding a player that actually isn't that good anymore.... Who is going to buy that?
After becoming a full-time activist (and being well compensated for it I might add) Kaepernick decided to invite all NFL teams to a workout in Georgia to display his football prowess.
Basically he ran around for a while and thew some passes followed by a Q&A session. I don't pretend to know what these things are all about. Here we are, quite some time later and not a single NFL team has contacted him with an offer.
If you are a Kaepernick hater, than this is probably great news for you. For me, i thought his antics were dumb but also not terribly relevant or important to the game. It all got blown up the same way that everything has been blown up ever since Trump was elected president.
I think it is pretty obvious: If you are going to be hated by half of the fan base you better be unbelievably talented and win some games. Colin simply doesn't have this attribute and I truly believe he will remain a free-agent henceforth. No one wants the sort of attention this man will bring to their franchise.