As someone who has taught themselves Chinese (lower intermediate level) as an adult, I agree with your assesement. An equivalent premise to this author's would

As someone who has taught themselves Chinese (lower intermediate level) as an adult, I agree with your assesement. An equivalent premise to this author's would be to say that the inconsistent spelling and grammar of English is a millstone around its neck. The mention of the 'character amnesia' issue is similar to the same drop in spelling ability we see in Western countries amongst people who primarily write using computers. I initially learnt simplified characters as I was travelling mostly to the mainlaind for work. Later, when I was doing more work in Taiwan, I picked up the traditional characters. It is not difficult as only some of the characters changed, and mostly it is the key radical that was simplified (like the speach radical 言) or else common characters like the default measure character 个, so once you learn these it is fairly simple to shift between the two (at least for reading). As others have noted in these comments, pinyin is not a substitute as it is not a 1-1 mapping. That is part of the reason why spoken Chinese differs from written Chinese, being less concise and more verbose to impart additional information to assist with the decoding from sounds back to meaning.