I can’t even pretend to be polite about this. It’s ridiculous.
Yes, some of the greatest SF/F writers out there love to read SF/F, some don’t.
As a writer you should love to read. If you don’t read you … it’s hard to explain but consider it Furthering Education or whatever the devil that modern phrase for it is when teachers are required to go back to college every few years kinda thing.
But reading should be something you love.
This and it’s myriad copies (seriously, I find it both terrifyingly cult-like as well as exceedingly telling that these are always worded nigh identically) are phrased in a way that clearly implies “so you known what is selling right now and you can write that”.
I call bullshit.
Don’t believe me? Follow editors and they’re all wanting to see something new and different and lament all the agents who’re only accepting the tried and true.
Look at how many clones of Twilight failed to garner its numbers. The Harry Potter knockoffs. Too, look at the insane number of people of all ages who prefer YA because it’s where they can find something different … to say nothing of YA not actually needing a special genre tag for “this isn’t depressing, dark, etc”.
In short the people like Ms Dawson who say this are horribly out of touch.
You want advice on writing? Look to the successful writers: Ed Greenwood, Neil Gaimen, Terry Pratchett, Spider Robinson, J K Rowling, Saladin Ahmed, Jeph Jacques …
What do they all have in common? They didn’t look at their own genre for anything. Not really. Pratchett’s Discworld stuff started out parodying Dragon Riders of Pern which is a fantasy novel, but I’m pretty sure that is not what the Dawsons of the world mean.
In many cases they utterly defy genre. Ben Bova acknowledges that Spider’s stuff is not, strictly speaking (and doubly so back when Ben was editor of a major SF magazine!) SciFi, but where the hell else could Spider’s stuff find a home?! It definitely wasn’t Romance, Horror, Mystery, or Western. It could be called SF/F if you squinted and turned your head upside-down … so, what the hell! True, Spider reads SF/F … because he likes a good Heinlein, not because it has anything to do with his work.
Ed Greenwood is a librarian whose home is packed to the gills with tens of thousands of books, all of which he has read. So, okay, yeah he reads Fantasy … and cooking, and architecture, and biology, and mystery, and horror, and poetry, and … he just likes books. And that diversity of tastes influences his work.
The thing is, do your thing. Whatever that thing may be. Try to sell it to an agent if you like, but agents are … no one’s sure why … a bit obsessed with finding the next big clone of the current hot trend; like it costs them anything to accept something great and just actually do their flippin’ job! But publishers won’t let their editors accept unagented stuff anymore. But luckily traditional publishing is really just great for an advance which is pretty paltry and for being distributed by Ingram which I probably misspelled and don’t care but is also pretty much the distributor for All Things Book for US audiences (sad but true, Reagan & Bush’s dismantling of antitrust laws was a Bad Thing … not that publishing much got enforcement of them anyway).
Still, as truly awful as they are (and words can’t express how awful they are) it’s as effective or more so to be available on Amazon which is easy enough to do. Though I’ll be damned if I’ll engage in the modern day slavery of Kindle Unlimited (exclusivity to Amazon and I make a piece if an arbitrary sized pie made of pocket change that Amazon sets?! Fuck that.)
But read what you like, write what you like. And remember: Ursula Vernon doesn’t read SF/F. But she writes it and can’t seem to stay off the bestseller lists 🤷♀️.