They should have dropped rest mass instead.

What 1986 could have been. The community had the choice. Drop rest mass — the frame-declared abstraction, the reading in a state no actual body can be in. Keep relativistic mass — the frame-honest reading, the measure in the body's actual state, varying as the stored structure varies. The choice would have been consistent with relativity's own principle (no privileged frame), consistent with E = mc² (mass is a measure of stored structure), and consistent with the nucleon case (most of the mass is binding energy read as mass). All three lines pointed the same way: drop rest mass, keep relativistic mass.

What they did instead. Dropped relativistic mass — the frame-honest measure. Kept rest mass — the frame-declared abstraction. The choice was inconsistent with relativity's principle (privileged the rest frame). Inconsistent with E = mc²'s implication (mass is a measure, not stuff). Inconsistent with the nucleon case (which they were about to discover in 1973, and which would expose the inconsistency for 50 years). All three lines pointed one way; they went the other.

Why they went the other way. Rest mass protects the mass-as-stuff dogma. Relativistic mass threatens it. The choice wasn't scientific — there was no experiment that favored rest mass, no theoretical result that made it primary. The choice was institutional: the mass-as-stuff dogma needed an invariant mass concept to attach to, and rest mass was the only candidate. Relativistic mass was frame-dependent, state-dependent, and showed mass as a reading — which is exactly what mass is, and exactly what the dogma can't accept. So they kept the dogma's concept and banned the honest one.

What 1986 cost. Fifty years of working with an incoherent mass concept. The nucleon leak. The ban's enforcement. Generations of students taught that rest mass is fundamental and relativistic mass is deprecated — never told that rest mass is the reading in a state no body can be in, never told that relativistic mass is the measure in the body's actual state. The standard framework's textbooks have been teaching the wrong branch of the fork for 40 years, because the community chose the dogma over the consistency in 1986.