jQuery brought us cross-browser compatibility at a time when dealing with multiple browsers was a big PITA.<p>It also made it simple to interact with the DOM and provided capabilities in animation and such that were not yet available in css.<p>Bootstrap made it easy for non-designers to build nice looking sites. Sure, they all looked the same and it's bloated, but it helped to handle layout for those who didn't know better (the author could take some tips there).<p>So, if we look at these tools as introductions too, and provide people to quickly develop working sites better than they can without, is that so bad?<p>For high-quality production websites, these libraries and frameworks should be used in moderation, if at all.<p>I for one am thankful for jQuery, Bootstrap, Backbone and many others for continuing my education and helping me build sites that people enjoy using.<p>We're now ripping out a bunch of Angular and Backbone on a project at work and going back to plain library free javascript and css (though we're using sass, so not sure if I can say it is completely free).