Apart from selection bias of readers, there is completely different kind of selection bias, by which the person posting here has some very positive or negative views for bootcamps. It is well known in surveys and reviews. If the person reading this post has gone to bootcamp 3 years ago, they are much more likely to write their experience if he/she have failed 100 interviews, or if they became CEO of the startup, rather than say work as an average programmer which is the most common outcome.