Why is wikipedia not considered a reliable source?

a)because there is not a printed version of it
b)because it can be easily changed by authors without expertise in the field
c)because too many people use it
d)because teachers say so

Read this passage from the online article “top 10 reasons why everyone is doing yoga” by kathryn livingston. what type of propaganda is the author using? why are so many people doing yoga these days? there must be more to it than endorphins; there has to be a deeper reason why 20 million plus americans have fallen in love with this venerable practice. here is my top ten list – and if you’re a yogi, i’m sure you can think of more.