First, any reason is not a good one. So, good reasons for affirmation are required. It follows, be reasonable. Given, proper netiquette to be reasonable with your likes.
Reasonable Content Earns Sensible Likes
Things happen for a reason. Make sure for a good reasons. Something is unreasonable if it is not done for a good reason.
This is not to say your reasons cannot be personal. It is to say that they should be based on fact. A fact is something that is verifiable.
So, our feeling are real. But, let us get in touch with them. Identify a particular reason for it. Make sure it is good.
Being reasonable when you click the Like Button adds value to your opinion and the material you like because others may Like it for the same reason.
Good reasons to Like material are the quality of writing, word choice and sentence structure. A powerful message or call to action for a peaceful non-violent cause is another.
Reasonably Good Content Netiquette
It is proper netiquette to Like content for a reason because it promotes your interests.