Again don't make it too complicated. Where I select where I want my airport geographically (or from a list of potential cities) should maybe influence weather (fog, snow, rain), simple terrain (grass, mountain, desert, ocean, city), and potential market if you wanted an advanced economic mode. However it would be cool if I could put my airport wherever I want (even if it didn't play too significant a role).
The other point by @Matyi10012 is you could select airport locations based on level of gameplay. "Easier options" include airports with flat approaches, easy geography, good weather) while "more difficult" options include weather, fog, mountains, less contracts/demand etc.
The focus of this game seems to be on the actual airport so maybe the location isn't critical at this stage.
Keep it simple and the answers will be easier!