Hi, Barry,
That is, AFAIK, all true except for maybe the point on the investors. I don't know who they were but there were some people who planned to make money if the Garand was dumped in favor of the Johnson. I have no idea why Ness hated Garand and the M1 so much. I think the article you read has the stupid statement that the Garand muzzle was tied to the receiver so the barrel bent like a bow when it got hot! Ridiculous, but some folks think lying in a good cause is OK.
The Johnson has some good points in its favor, primarily the ability to "top off" a magazine. Even that was rather theoretical, though. Ammo would have been issued in '03 clips so unless at least 5 rounds had been fired, clips would have had to be broken up to "top off." I think Johnson would have been better to promote the detachable magazine rifle, a system the U.S. eventually went with (M14, M16). Still detachable magazines have their own problems - they are not shipped loaded (M1 Carbine and M1911 magazines were not) so they consume shipping weight and space. The rifle is useless if the magazines are lost, but the same is true of M1 clips.
But ammo was shipped in M1 clips, and the shipping size and weight are not significantly greater than those of the ammo alone.
Another problem with actually adopting the Johnson would have been the need to establish a whole system of manuals, soldier and armorer training, spare parts supply and the like. That work had been done or was well underway for the M1.
As you say, we don't know how the Johnson would have worked out. I don't think we can necessarily compare it with the very limited use of the Johnson LMG. As with the Johnson rifle and the M1, the LMG may well have been better than the BAR, but the BAR existed, in quantity, and there was no real need for another LMG.
As the owners of both rifles (I own one Johnson, and five M1's), I think two areas are of interest - disassembly for cleaning, and overall handling. Have you ever really taken the Johnson down to the point needed for cleaning after a month of fighting, in other words to the point you would disassemble the M1 under the same conditions? And have you ever tried to sling one for a long march, or do the manual of arms? In my opinion, which most folks here seem to think is pretty worthless, the Johnson fails as a really usable battle rifle, no matter how many theoretical good points it might have.
Some folks have insisted that there was no reason not to adopt the Johnson; the problem as I see it was that there was no very good reason TO do so. Even if it had been better in some way, it was just not ENOUGH better.
(P.S. The current value of the Johnson as a collectible has absolutely no relationship to the question of its suitability as a battle rifle.
Another P.S. The rifle that "fixed" some of the problems of the M1 was the JapaneseType 5; it had a ten round magazine and could be loaded with loose rounds or from 5 round clips. Simpler rear sight, too.)
Jim