Our brain naturally draws parallels between things when we try and rationalise them. I think it is a fair call to call yourself the "Airbnb of X" or the "Uber for X" - I do agree that some people take it slightly too far and it has the opposite effect of telling people what you're about. People can rationalise and understand "Uber for vets" or "Airbnb for last minute hotel cancellations" or "Snapchat meets email" - but when you take it a step further and combine multiple concepts into a tagline it becomes a soup bowl of nonsense.