That's crazy, right?!? And yet, honestly, many authors do forgo television in favor of reading, writing, or researching topics. In my opinion, Wikipedia is a tribute to millions of experts in certain fields who took the time to write - and many of them are probably authors of various other types of works, including journal articles and books.
Next time you use Wikipedia, see if you can locate the author of the page. You might be surprised to find out how versatile the writer is!