But JAPAB, while it is true that words have the meaning ascribed to them by humans, those words have commonly understood meanings. They do not exist in a vacuum for us to choose to ascribe whatever meaning we like to them as and when we want.
What typically happens is that words have a traditional meaning, some people think those are restrictive in some way, and campaign to have them formally widened out or changed.
It happens when people object to,say, a definition of Scottish which requires the person to be born in Scotland. Or when people object to a definition of marriage which says that it is the union of one man and one woman.
You, I or the next person may disagree but that isn't the point here. It would be misrepresentitive and straw-manning to portray people as if they believe you can change your place of birth say, just because they think place of birth shouldn't be a barrier to you identifying as Scottish.