A lot of what fans think is canon just isn’t anyway. Most so-called ‘violations’ are just different interpretations of what was shown on screen decades ago.
There’s an entire list out there of all the headcanon that fans hold up that just isn’t supported by what’s on screen.
Writers shouldn’t be held to fan interpretations of what they thought they saw in TOS or TNG.
In other words, fans who clearly live in glass canon houses shouldn’t throw stones.
Well there’s that too.
Gene found it totally cool for previously unmentioned immediate family to show up out of the blue, but fans can’t help going into spasms when things not previously mentioned show up.