There were lots of reasons why the fetish element was not acknowledged.
But the main one was that, if people acknowledged that many of them were men with a sexual fetish, that undermined Stonewall's line of Acceptance without Exception because those men would/should have been excepted.
So...
A) women could have reasonably argued that all TW should be kept out of women's spaces on the basis that some were real transwomen and some were autogynophiles from the start.
B) because it would have been harder to get the general public to feel that this was 'the most vulnerable group' if it became known that some were doing it for sexual gratification reasons.
C) it would have most definitely ended any talk of TWAW if so many of them could be proved to be just common or garden sexually motivated males.
I'm always most baffled by the TW re all harmless and don't commit crimes narrative when the evidence is freely available that there is no significant difference between offending rates or patterns between men and TW and that the rate of sexual/violent offending against women in TW is actually higher than the rate of sexual offending in the general male prison population. Meaning that a TW is more likely (not less) to be in prison for a violent/sexual crime against women than other men. Or other crime.
That's not to say I think all TW blah blah but the lack of critical thinking applied by so many was just baffling.