What Mr. Bradbury says here is something I wholeheartedly agree with. The problem is that doing both these things--writing every day and reading intensely--are not always easy to accomplish. Life gets in our way. Even so, this is something for writers to strive for.
I know that I have cut my reading time since I started writing. Didn't cut out reading altogether but I have to be more selective in what I read and create time to do so. It helps that I happen to be a pretty fast reader. I do look for bits and pieces of time where I can read. Think of all the places where you sit and wait. Doctor's and dentist's office, airports, pre-game times and more. Why not take a book or your kindle along? Might as well put that waiting time to good use. I even read while waiting for a tray of cookies to bake.
As writers, we read with a different perspective than most readers. We tend to mentally critique as we read. I really hate that I do that sometimes but it's just there. We also quietly applaud in our minds when we read a particularly well-written portion of a book, one that has prose that sings to us.
I urge all writers, including myself, to write every day. It doesn't have to be 1000 words or 2 chapters or a complete article. It might only be a journal entry or a short poem. It's still writing. If you do no more than one writing exercise, it's writing (and learning). I consider my posts on this blog five days a week to count toward my writing daily goal. On the week-end, I try to write something, too. Do I always make it for a full seven days? No, but I do it the majority of the time.
When I've been ill or had a crisis of some kind and have had to put writing aside for a week or more, I have a harder time getting back into the habit. Once broken, it's hard to fix! So, if you follow that writing daily advice, you'll develop a good habit and you'll reap benefits.
A number of years ago, I had to stop writing for several weeks. I was bedridden for a full month prior to surgery for a herniated disc and severe sciatica. Even though I couldn't write during that period, I read and read and read that month in bed and then during my recovery period. When I did get back to writing, I made sure I wrote something every day.
Set a goal to read more and to write daily. Grocery lists do not count!