No.

Wikipedia is an encyclopedia, really. Its no different than the Encyclopedia Britannica in many ways. Sure its cheaper (free-er?) and more accessible, but it contains virtually the same amount of information. Further, many good wikipedia articles are themselves written by experts or well read amateurs, and are a synthesis of several secondary sources.

Where real history lies (according to the modernist school) is in the primary documents themselves. These are letters, notes, diaries, testimonials, or anything produced by a person or event in question. As long as they exist, and professional historians dont simply reject that approach completely, then professionals will continue to ply their trade. As far as academic history goes, it is unconcerned with Wikipedia or the information contained therein. And from academic history trickles out most of what we know about the past.

Now, for some that will come from reading academic history, and for others that may come from reading the Wiki page written by the guy who read the academic history, but thats all okay. What really matters is that people are reading, and their interested in the past. As far as I am concerned, Wikipedia, Reddit, and sights like them are actually a really promising development in "popular" history. People can contribute to Wikipedia to make it more accurate, and the curious can come here to learn more about what really happened. As long as Wikipedia, Askhistorians, and places like it maintain a basic level of quality and knowledge, I cant see how they could be a problem.