I'm (slowly) learning that nearly everybody tends to make decisions for one reason, then rationalize those decisions with something that sounds better. I do it a lot without even realizing it-- and if I do it long enough, I start to think I arrived at my decision because of the rationalized reason rather than the real one.
It's my suspicion that we (collectively) do that a lot, in regards to a lot of the "good enough" arguments we have here. Rear brakes are one of those things-- there's nobody anywhere that will argue that discs aren't better, but no shortage of arguments as to why drum brakes are "good enough".
Original 356s had drums on all 4 corners-- not because they were better, but because they embraced a proven 1950s technology. Nobody is arguing that we should do the same thing, because it's universally agreed that discs are better, and on the front it's a low-cost replacement. Everybody knows that the majority of braking force is in the front. In a normal vehicle, that's perfect, because the bulk of the weight is there as well. That's not the case with a speedster. These cars carry very little weight over the front axle, so the rear becomes a more important part of the equation.
I know my car is a rolling anachronism, but driving it briskly is one of my great pleasures in life. Doing that with brakes that I'm not 100% sure about seems like rationalizing that Russian Roulette isn't really that dangerous, as there's only a 1 in 6 chance the chamber has a cartridge in it. I can understand skipping the big engine, or deciding that 4-lug wheels are good enough (they are).
But economizing on brakes is not something I'm ever going to think is a good idea, no matter how it gets dressed up for church.