Bill Gates stated that the Bitcoin is the future and that it is better than currency. Would you assume that his statement (as one of the many reasons) added value on Bitcoin which made it stronger and more stable in the system? 
I think so because some people would just believe a certain product or service when famous personalities are supporting it as well. Being one of the owners of Microsoft, Bill Gates has a big impact in convincing people to invest in bitcoin because just a word from him would even compete to the non-famous people who are saying that bitcoin is not worth it to invest before. The exposure of bitcoin in various type of media nowadays gives people more reason to look into it and later invest because they don't want to be left out. All the positive views of famous people predicting bitcoin going up at the end of the year gives people the reason to invest into it realizing that they don't want to miss this opportunity of a lifetime.