OK, a lot to unpack here, but I divided up your post into the 3 ideas that bear analysis, IMO.
On #1, the lesson that should have been learned by this front office is to know when you have scant competition for a player's signature, and when there will be PILES of teams trying to sign a player. In the cases of Abreu and Robert, there were few suitors, and NONE among the moneyed class of MLB. For that matter, there was scant competition for Machado and Harper, but they fvkced that one up, unfortunately. Turning to THIS offseason, for Cole's signature, I can envision the yankmees, the scrubs, Atlanta, Philly, and Texas, and LAAAA all being interested, and all having more money to spend, and all being closer to competing than the SOX. Part of winning FA is identifying the player, and part of it is signability.
If you've been a shitty team for a decade, AND reluctant to spend, your chances to sign top talent in FA are remote. [Unless there are few competing suitors.]
On #2, I don't think that the free agencies of yesteryear are all that cogent to today's discussion, in all honesty. There are MASSIVE differences in the CBAs, for example. [Dye would have had a draft pick attached to him, were he a FA today.] There aren't NEARLY as many stupid front offices in MLB as there was when AJP was stupidly given away for free. Were it TODAY, the SFGs would have rightly tried to keep AJP to rebuild his value, THEN trade him away. As for Fisk, that was so long ago, if memory serves, he was only a FA because he came off an injury.
Free agency [both MLB veterans and International FA] have long been a massive failing by this front office.
Lastly, on #3, this front office crapped their pants on the pursuit of Machado. In no way was their incentives-based deal a good one for Machado. And in no way was this org worrying about a $300MM guarantee cogent, given the natural inflation of top player salaries and the $/WAR for either one. Sorry, but it was a MASSIVE fuckup, and one that will haunt this team for a long time. There won't be another 26 year old stud available in FA for YEARS. There won't be another 26 year old stud, AND none of the RICH teams interested/involved for decades. If you want to behave like a "small market team," then you'd better learn to strike when you can.
This front office has earned the criticism and scorn, and we are RIGHT to pile it on them until they prove otherwise.