Comment by simonw
I'll offer the opposite perspective. People writing about stuff that they are currently learning is often better, because they have a much clearer model of what's obvious and what isn't.
Someone with 20 years of experience with a technology will usually have a much harder time re-connecting with that beginner's mindset and doing a great job of providing the information that other newcomers most need to understand.
That's not to say that there isn't plenty of junk content out there, but I blame that more on inexperienced writers than on people who are writing about technology that they don't have a great deal of experience with.
A great writer should be able to write about something while they're learning while still producing content that's genuinely useful.
But they should still present themselves accurately, because at that stage they don't know what they don't know and they may be misleading people without realizing it.