If your justification consisists of 'the other guy might do it first and reap the benefits', maybe you should rethink how you apply ethics in everyday life.
By 'reap the benefits' did you mean 'extort you based on your brand value'? Sure, there are laws now that prevent domain name squatting, and most platforms would give your brand to you anyway (provided you are big enough). But why go thru expensive hassle when you can solve this proactively?
All companies do that by registering their trademarks. I don't see how this is different.
All companies do that by registering their trademarks. I don't see how this is different.