Secret Targaryens and Blackfyres

I feel like I'm the only person who isn't a big fan of the Jon Snow is actually the son of Rheagar Targaryen and Lyanna Stark idea and is still hoping there is a chance it's not true in the books.

I'm not one of those people who confuses their fan theory preferences with the definition of good writing and so claims a series is pulling stuff out of it's @$$ when that's not what happens, in the books R+L=J is a plausible explanation of the clues we have so far, probably the most probable, whether one likes it or not.  I am less critical of how the TV show ended then most people in general, and the criticisms I do make have little to do with it going this route, and where it is relevant is more that they didn't do more with it.

The rising through the ranks real hero of the real battle most of the world is ignoring being the secret true heir to the throne all along is frankly way too conventional for what a Song of Fire and Ice's whole mission statement is supposed to be, it just turns Jon into Strider instead of the Bastard who overcomes all that anti-Bastard bigotry.

And then there's how his existence is supposed to be the proof that even Ned Stark is imperfect, peoples perceptions of Ned are originally the main reason so many felt there had to be more to it.  But the thing is we know that Ned and Cat were not in love at the start of their marriage, it was Brandon Stark who Cat had been in love with.  I don't think it's at all out of Ned's character that he may have loved someone else back then.

But perhaps my biggest problem over all those is the implications it has for Lyanna Stark's character.  The books even more then the show compare her to Arya Stark, and to me that comparison makes her being another woman who's crowning achievement is to die giving birth to a more important male character pretty unfortunate.  So I definitely do believe she should be the Laughing Tree Knight and that her relationship with Rheagar was consensual, but most importantly she really just didn't want to be forced to marry Robert.  Ned was keeping a secret about her from Robert, but what if it's that she didn't even really die?  What if Arya is going to meet her in Bravos, or Dany in Mareem?

The other main character somewhat popularly speculated to be a secret Targaryen is Tyrion, Alt Shift X has a video on that theory that covers the reasoning behind why it exists but also why it thematically doesn't fit.

But then there is the matter of Young Griff.  No one thinks he is actually a son of Rheagar and Elia as he is currently officially claiming, their kids were definitely all killed by The Mountain.  But the popular fan theory is that he's actually a Blackfyre, a rival branch of the Targyrens that is also assumed to be extinct now, think the Jacobite exiles during the 18th Century.

I find it such an odd theory, why would a legit Blackfyre claim to be something else?  The Blakcfyres already claim they were the real true royal line all along, and certainly have a better claim then the Baratheons.  It really is a much simpler explanation that Young Griff is just a fraud, like those who claimed to be a secretly survived Louis XVII, or who claim Bonnie Prince Charlie had a secret marriage, and there's even an example of this going back to the War of the Roses connection in Perkin Warbeck.

The main evidence for Young Griff having a Blackfyre connection is his having the support of the Golden Company, the argument is they were founded for the purpose of carrying on the Blackfyre cause and that their now supporting an alleged Heir to the Blackfyre's enemies therefore makes no sense.  But again in real life there have been similar quasi military organizations founded with a very specific purpose but who moved on to a new one when the original purpose became Obsolete, take all those Chivalrous Orders who's original purpose was dependent on the existence of the Outremer States, when those States ceased to exist they found new purposes.  

It could be that at this point the Golden Company just really wants to finally successfully conquer Westeros, or that they just became mercenaries and are doing it for the money Illyrio Mmopatis is paying them, or a combination of both.