There has to be more to it than the question, because you can trivially ask it of every theory ever. The paper at least brings something new, pointing to detailed inconsistencies in the theory - it has lots of actual work behind it. Just babbling on about "it might be this or that" doesn't.
Leonard Susskind is famous (as physicists go) for making outlandish claims every five years or so, which then later turn out to be true. But of course it's the latter part that makes his claims interesting, and as he's said "maybe that's because I spend those 5 years working on the problem first". There's a lot being debated about black holes.
Debates/controversies between the likes of Susskind and Hawking are interesting, because you know they've brought deep understanding to the problem before asking the questions. But the internet is chock full of people who are convinced that they've found the flaw in relativity or QM, and most of them bring as much to the discussion as the Time Cube guy, and make about as much sense.