Scam is something that don't worth anything, bitcoin is worth $8,300 right now so I don't believe that it is a scam. The price is based on popularity to it's users so as long as it has demand it will always have a value. I don't think that the people who already invested on it will let that value go down.

When someone with bad intention or some hacker gain access to the bitcoin system then it is possible. But time and time again bitcoin prove its worth to the people bitcoin has a huge a mass of support from some of the business in the world some are accepting bitcoin as a mode of payment would some business trust a scam I don't think so. If you were in business industry and if you are running for a long period of time and have been continuously increasing it's value through the years would you think it's a scam I don't think so.