[neilkk]

We only have Otto Frank's word for it that this is what she would have wanted. And he is known not to have had respect for her legacy in every way, for example editing the diary to remove criticism of himself.

Also, 'wanting to be a writer' does not necessarily mean that you would have wanted to have a specifically private piece of writing published.

[parineum]

Even if he's a liar and she didn't even want to be a writer, at least he left a plausible reason why it might be what she would want. In the absence of her actual wishes, that's the best we can do and, given the impact that the journal has had on the world, I find it hard to believe that anyone would not want that work published.

This, on the other hand, is someone going against explicitly stated wishes. It's not a very comparable situation.

[neilkk]

So the requirement is simply to come up with 'a plausible reason why it might be what [they] would want'?

[parineum]

I'm not saying it would be uncontroversial but it'd be a hell of a lot better than doing the exact opposite of explicit instructions.