Sure, but that's not what Loeb is doing, particularly. He's over-interpreting the evidence, under-investigating other alternative hypotheses save to shoot them down (without adequately exploring the possibilities), and generally raising an important idea worth considering but in a way that is generally not adequately conducive to rigorous scrutiny. Many of us who live deeply within the experimental sciences find the approach distasteful in part because we've seen colleagues mislead over and over and over again by the attitude (albeit usually in a less public way).

Even if there is a gate, it's not necessarily because the grass is greener on the other side.

What one wants is not to tell Loeb to shut up and go away, but be a (more) proper scientist: come out with increasingly good light-sail models which are tested rigorously against all the evidence to constrain which part of parameter space a light sail would fall into.

The epistemologically grounded approach to 'Oumuamua is better exemplified by this article on Medium. It's slightly less charitable than it could be, but it's a lot closer to the ideal of assembling a variety of hypotheses, comparing them with data, and being up-front with our uncertainties.