No metrics are perfect but I highly suggest following francois chollet (fchollet on twitter and hn, creator of keras) for his monthly updates. He does a pretty good job of showing actual activity on github: https://twitter.com/fchollet/status/753980621823750145 I point this out because drive by stars of a project are easy...but it doesn't reflect actual user activity.
This is true. Stars in this context are also more indicative of projects that are attractive to a more mainstream audience. Examples like Deep Dream and Neural style, where laymen visit the Github page and star the project because it's "cool" are prominently featured, while projects like Torch and Theano have had massively more impact on the deep learning world today.
"Popular Deep Learning GitHub Projects" would have been a more accurate title. It is mentioned in the text but the title mentions "Top" which gives a different impression than the word "Popular".