We might be talking past each other.
Before MDMA was ever synthesized, there were human brains where the compound would not be as effective. (I seized on the "everyone" part.)
Your assertion.
And you missed the point.
Regardless, if your assertion is correct that there are some human brains where MDMA is not as effective, it is immaterial to the question at hand.
There's no definitive measurement or process to identify the subjective euphoria and effects of MDMA between two individuals (the effectiveness of MDMA as you put it).
There is no way to actually determine that one brain would have less subjective effects than another. That's why it's called subjective and not objective.
Without being able to compare pure racemic 3,4 MDMA to something that isn't, NOBODY would be able to say whether or not something is MDMA or mehDMA, from subjective effects. They literally do not have the experience with actual MDMA to make that assessment, regardless of how their brain works on it.
And your assertion about hitting everyone's buttons while it has some merit with respect to paradoxical reactions like desoxyn for ADHD; the sympathomimetic, euphoric, and psychedelic effects of phenethylamines like METH, MDMA, MDA are highly conserved at recreational doses. That's why doses of methamphetamine for ADHD are usually in the 5 to 10 mg per day range, whereas a single administration of recreational MDMA is 125 to 150 mg, and a single administration of recreational methamphetamine is 30 to 50 mg.
I challenge your basic premise as not being consistent with the known effects profile of MDMA and other phenethylamine stimulants. If and that's a big if there are people that 150 mg of MDMA does not affect, they're probably at the 0.1%-0.01% of the population. The reported incidence of mehDMA is much higher than that.
All science and signs point to it being in descending order of likelihood:
1a. Not MDMA for whatever reason, but rather is MDE, MDA, a Substituted methcathinone, a Benzofuran, etc.
1b. Adulteration (reagent testing kits, or sent away to a lab is necessary if you want to know what you're taking, or have a reasonably good guess)
2. See #1 above and add "not the same dose"
3. A Regioisomer, there are 18 known for MDMA that cause enough problem with actual lab testing that the DEA created a 400 page document detailing how to create specialized procedures and processes to capture these isomers that break down identically in the same way with respect to GCMS as MDMA. PM if you want me to send you the link to the paper I'd have to dig it up.
4. I put this one after the regioisomers, because I think it has the least likelihood unless people are just extremely unlucky.
MDMA from a stereoisomer (enantiomer) asymmetric synthesis, or somebody decided to waste time and money creating (R,R)MDMA(bi?)tartrate and (S,R)MDMA(bi?)tartrate,
then separating the diastereomers, then basifying and recrystallizing with HCl to come up with stereo isometrically pure both (R) and (S) MDMA.
Simple evaluation of drug samples sent in to free testing sites that identify how vast numbers of pills sold as MDMA, powder and crystal sold as MDMA, that actually is not MDMA, is adulterated with multiple other drugs, and/or is low quality/ purity, points a finger squarely at human error.
The people taking what they thought was MDMA erred.
As far as anecdotal reports of drugs testing as pure MDMA via GCMS, I have captured that above, however, I would again say human error or even operator or equipment error.
People seem to think that just because you have 100 pills from a particular press they are homogeneous. They are likely not, and you should not expect them to be.
Just because somebody sent a pill in out of a lot that looks the same as all the rest doesn't mean that it's the same as all the rest. The pill sent in could test pure, the ones left in the bag not so much.
Pill counterfeiters explicitly make their pressed pills look as close as possible to real MDMA (color and press) so that they can scam people.
Dealers, not the most scrupulous people in the world, have been known to mix known counterfeit pills with good pills to push up profits, then they could just blame it on mehDMA.
After all, that one pill that got sent in tested good didn't it?