The predictable reactions ranged from "Who cares, it's impossible to prove or disprove", to "This is pseudo-science, these people are bad scientists and should be ashamed". I think both statements are wrong and too many take them for granted.
Let me start by admitting that currently theories like VR world are not scientific. But that is simply because science is usually defined as "things that could be subjected to scientific method". Just because right now we can't think of any experiments to test these theories or any new predictions that these theories make does not mean we never will. Science is full of examples when seemingly simple problems could not be solved for centuries and I am sure many felt tempted to say that "maybe these problems can never be solved" only to be proven wrong. So to me it seems like thinking about currently unscientific models and trying to bring them into the realm of science is something scientists should do, and it should be respectable work. Working on such seemingly absurd topics does not make you a bad scientist, only a courageous one; you would only be a bad scientist if you were spitting out propaganda and claimed that these theories are scientific and plausible now.
Also, think about this: people who go around saying "all such theories can never be proved or disproved" are themselves making a statement which is not known to be either true or false, and trying to make it sound like it is a logically sound statement. To me they do qualify as bad scientists, spreading a false claim. Until somebody conclusively and logically proves that all the non-traditional theories about the nature of the Universe are not verifiable, I will continue to put these people in the same bucket as religious zealots banning evolution in schools. The only theories which cannot be proved or disproved are the ones which were never formulated: for example, nobody ever defined what God is or supposed to be, so we got nothing to work with if we want to prove God's existence. But once you formulate a theory (like: world if VR) you are in a completely different realm.
In conclusion: it is a respectable effort for scientists to think about issues related to the nature of the Universe and try to build a bridge between alternative theories (like VR world) and today's science. The fact that such theories are not science today does not mean they can not become science tomorrow.
It seems especially ironic that alternative theories continue to get ridiculed by 'science' zealots while in the meantime humans themselves have come very close to building an artificial universe. If we can already build a rat's brain cell replica inside a computer, how far away can we be from building an exact copy of human brain, except represented as a computer program? How hard would it be then to feed this 'software brain' with whatever inputs we want and make it believe it lives in a world we simulate? So maybe instead of ridiculing Matrix-like theories of the Universe, we should realize we are about to create such "matrices" for others - so time has come to start thinking how would we test our own environment for being Matrix-like.
Finally, there is a direct connection between such efforts and religion. If ever we are able to find strong confirmation for one of the alternative theories of the Universe, it could simultaneously confirm and overthrow the belief in the existence of God. For example, if we discovered that our entire Universe is just a computer simulation run by some other beings, it would confirm many things that religions taught us about the world (such as an Act of Creation or presence of some ultimate all-powerful being) but it seems to me that such a revelation would nevertheless be considered a disastrous blow by many who believe in God.