There were alternatives. IMO, Microsoft Cntk being one which was better than tensorflow. Tensorflow 'won' because of herd mentality and the perception that everything google does is cool.
I concur. Main issue I have faced is people down voting questions even when the question is perfectly valid and reasonably well explained(imo). It sometimes looks to me that when a question is about 'under the cover' stuff and not superficial 'how do i get this done/i did this but got this output', it would be down voted.