"And there is no reason why people should not be free to find many unique ways of defining what "God" means to them."

Except that so many people intend that their personal definition should be the one accepted by others. It is a bit different than defining 'antique' or 'large' ...or 'folk'. There can be disputes over those, but seldom wars waged over them.

My opinion is that within a specific discussion, the word 'God' needs to have an agreed on definition or, as JtS said, conversation becomes quite awkward, if not meaningless. I suppose it is possible to just have a discussion OF the idea of 'personal concepts of God', but that is not the usual thing.