I decided, after lurking for years, to make an account just to comment on this. I'm a sportsball fag, and know a thing or two about handeggball. This could be long, so apologies in advance since I'm not sure how to use the "spoiler" tab yet to keep it contained - still figuring things out.
Kaepernick not being signed is an easy thing to figure out. Ignoring all of the political stances he's made (which, yes, has to do with him being unemployed; however, it remains to be seen how much it affects his chances), he is not the typical QB that teams are looking for. Kaep's claim to success is because of the "Pistol" offense that was popular for a few teams in the NFL starting around 2012. The Pistol is no longer used in playbooks. Maybe a play or two, but that's about it. The Pistol combines college football's Read-Option with the NFL's Shotgun set. Generally, you need a fast QB (lol Peyton Manning was forced to use it in his last season, slow son of a bitch), which Kaepernick is. However, once NFL defenses figured it out (and they are very, very quick at doing so), Kaepernick was exposed as a one-read-then-run-for-the-hills QB.
BLM and SJWs that don't watch football will scream "but muh stats" and "muh Super Bowl appearance" and whatnot. Yeah, Kaep's stats, compared to other starters and backups, are pretty solid. Not gonna lie. However, his stats are artificially inflated due to being behind in a lot of games, thus the defense will get lax and a little lazy due to not wanting to risk injury. Also, his interception rate is low because of Kaep being a straight pussy and refusing to throw if his first option isn't open. He'll just run. And that Super Bowl team, he had an outstanding defense, a fantastic offensive line, and a solid running game. All of those are a QB's best asset, young or old. Remove his head coach, take away that defense, the running game, the OL, etc., and you get a guy that can't even get his team within sniffing distance to the playoffs, let alone another Super Bowl. Compare this to guys like Brady, Manning, and the other elite QBs that essentially are the reason why their teams are, or were, so good.
Now with BLM and SJWs freaking out over teams with injured QBs that don't sign him (Dolphins, Ravens), that's easy too. At this stage in the offseason, it's way too late to try to grab a QB. They missed minicamps, offseason workouts, etc. Hell, the preseason started and the regular season is only a month away. And whenever a team's starting QB goes down, they try to replace him with another QB that is very similar to the starter, or knows the system. Flacco goes down, is out maybe a week or two, and all the BLM fucks are screaming to get Kaep in there. Lol nah. Just sign an Arena League QB for wayyyyyy less for a few weeks. Tannehill goes down, same ordeal with the REEEEEEEEs, but Cutler, the WHITE MALE that they replaced Tannehill with, knows Adam Gase's system already. Minnesota's Teddy Bridgewater, a QB that specializes in short, timed routes went down last season. Who did they replace them with? Sam Bradford, a QB that, well fuck me running, specializes in short, timed routes. See where I'm going? Guys like Kaepernick and RGIII won't find teams, not because of their skin or political views, but because they fit LITERALLY ZERO OFFENSES. And fuck me if a team is going to completely tear down their system just for a backup QB. Fuck outta here with that.
It's sad, because Kaep really did look like the next big thing years ago. He's very athletic. He just got absorbed in a mountain of bullshit, and now they're using him as some kind of pariah. Brainwashed, is what he's become. Once his usefulness runs dry, they'll throw him out in the streets. Just like with every other movement that has ever existed throughout time. Kaep is easy for them to use, because all these fucks gotta do is look at the stats and scream. Stats never tell the entire picture. Ever.
tl;dr: Kaep is not a good QB. No team is gonna restructure their entire offense around him. Period.