I love how these "developers" who apparently never had to develop a complex layout just hate on stuff they don't comprehend.
I mostly use Bootstrap, specially the utilities like the grid and I use a lot of these classes. It simple makes your job easier and plot twist, if you endup migrating you CSS framework without any need I got bad news for this fellow.
Yep. Bootstrap is a great example of how developers of different walks of life and different levels of experience are able to grasp helper classes easily.