I confess I don't know all the ins and outs of the organization, but I thought it was more along the lines of the voting partners of BRI basically sided with Mike on having the touring license and kind of made him the captain of the brand. Neither Carl nor Brian were deeply invested in piloting the ship.
I think "Summer of Paradise" happened because it was something to do and there was no real resistance to putting out product, but it wasn't that Mike necessarily had complete control. But Landy's Brian was focused on solo work, Carl kind of lost motivation after the band went oldies (and especially after Dennis died). Al may have resisted elements of the situation, especially with live performances / cheerleaders, but he was the only one perhaps positioned to combat Mike. And however one looks at it, Mike has certainly been more of a face of the brand and IS a family member, so he has a bit more pull than Al.
Again, just my basic understanding, and I would not be at all surprised if I am wrong.
As for Carl, the Brian/Paley material, I've thought about this one a lot.
Here's where I land on it ...
I don't think Carl disliked the material. I don't even think he necessarily resented Brian being back in the big chair. And honestly, I don't believe he saw more value in Stars and Stripes, Vol. 1, or in Summer in Paradise, vs. the Paley material.
I think Carl saw a chance of history repeating itself, and this time he said, "That's enough."
From Brian's 1964 breakdown to the Smile meltdown to the 1968 mental disintegration to the Holland struggle to the Brian's Back circus to the "no really, Brian's really back this time" of KTSA, to the return of Landy ... all Carl ever heard was, "Why didn't the band do this, why didn't the band do that, why did Brian get rushed, why was Brian turned back into a performer, why was Brian forced to produce material, why didn't the family stop this, why didn't Carl do XYZ," etc.
Then there was the faux autobiography, the lawsuits, the press, and all anyone could agree on was that things were completely screwed up.
Carl may have seen renewed interest, a new collection of material, Brian at the center and he may have thought to himself, "What if this goes sideways like it has the last twenty years? What if he loses interest and I have to finish the product? What if Brian crashes even harder? What's Brian's mental state? Is he on the right meds? He's smoking again and he's gaining weight, are people going to compare this to 1980-82?"
I think Carl was in a no-win situation. And the only way to basically control the situation and deflect attention on a possible mess was to shut down the project.
I'm not saying this is 100 percent what happened. But I put myself in the place of the caring brother who has watched his sibling soar close to the sun, crash to earth and try to take flight again like a phoenix, only to burn again and again ... What would I do?
We also can look at release timelines. There was a 5-year span between KTSA and BB85 (granted, Dennis died in between), there were 4 years between BB85 and Still Cruisin' (and that wasn't even a full album of new material). So really there were 7 years between BB85 and SIP. Four years after SIP came Stars and Stripes Vol. 1 (which isn't a perfect album, nor even a particularly inspired project, but it didn't require much investment, it followed a similar project with the Eagles, and had the potential to grow into a new market). Less than 2 years after that, Carl was dead.
Maybe the Paley Sessions material would have blossomed after SAS after the band and Brian and Paley woodshedded the material more. Was, in the 50 Sides book, even takes the blame / falls on the sword for telling Carl and the band that he thought the group could come up with better material.
Carl got sick, Carl died, Brian went full into his solo career and that ended the Paley Sessions hopes for a Beach Boys project.
All I'm saying is that I don't think the decision was simple, I don't think the decision was even really made ... no final decree from Carl that this material would never be recorded. I think they were looking for a chance to try something and take the time to make a good original project, but then time ran out for Carl.
Maybe I'm trying to give Carl way too much freedom. But the dude was a beautiful voice, a true musician and had certainly led the group through rough waters ... I don't think he necessarily thought SIP was better than Paley, I think he was trying to be careful and avoid another exploitation circus and maybe actually buy the time for the band to really make something special. It's just that the special project never had the time to happen.
My two cents, worth much less than that in today's economy.
I end with a caveat: I am always wrong.
So anyone who disagrees, I don't take it personally.