I think this is where a lot of younger folks get frustrated. They come out of school or enter the business, think they may know a better / smarter way to program, they believe that if they format to fit their particular tastes in music or their thoughts on programming that surely others will buy into it as well, etc. While certain facets of radio programming do evolve and change over time, as others have pointed out above, there generally are reasons that certain choices or decisions are made or programming is done.
It's also often the case where younger folks may think their ideas and concepts on programming are original and will help improve the industry, but in most cases they're not so "original" and with few exceptions, their ideas have likely already been tried and proven not to work well - Expanded playlists, throwing in an occasional random song as a "curveball" (which, rather than "delight" audiences, may simply cause them to switch off your station), trying to "educate" your audience by occasionally exposing them to new or different music, rather than doing research and giving the majority in your target demographic what they've told you they want to hear, etc. That doesn't mean that all stations' programming is perfect, or that PDs/MDs get it right every time and there are some that do it better than others, but in most cases there is a method and real thought behind what you hear on the air.