The online Merriam-Webster dictionary has the following definitions for the word inspire
- to make (someone) want to do something
- to give (someone) an idea about what to do or create
- to cause (something) to happen or be created
- to cause someone to have (a feeling or emotion)
Therefore, it follows that an inspiration is a person who inspires others. It seems based upon the definition that to be an inspiring person is a good thing. Someone who makes others want to do something, or create or even be moved by emotion.