I think some of this has to do with folks getting into photography, which has become increasingly more accessible and affordable, without learning the craft and the technique - this leads to settling for mediocre results and possibly dressing up the image with "artistic" effects and calling it "art." There is a craft to photography and image making. Sliding sliders without understanding the motivation behind those moves may make something that you or your mom or your friends like and think is artistic, but it is probably not art.
One can argue about "what is art?" but an image that demonstrates that one has mastered the craft of image making will be objectively apparent. One of the most critical aspects of mastering the craft is learning to accept and understand critique. Even if you strongly disagree with someone's critique, it will often lead you to think about your craft and your image making outside of the very specific context of the critique of that one image. The idea of creating "art" is highly personal and can evoke emotional responses to critique that might make the artist shut down and not listen. It takes an open mind to listen to, and process, critique and take from it that which will help your craft evolve and improve.
In terms of post-processing, one often sees someone post a question about Lightroom or Photoshop tutorials - how do I get started? I cannot even imagine trying to tackle these applications without having a basic understanding of how to evaluate an image and visualize the changes and edits the image might benefit from to make the image the artist had in mind, regardless of the software one uses to do so. In other words, learning what the clarity slider does without understanding why you would want to use it is an exercise in luck more than deliberate image making. That's a tough way to make an image that satisfies the artist or the artist's client.
Finally, styles and trends in processing change over time. Finding one's own style takes time and may change and evolve as the artist explores the medium and discovers new techniques or methods to express their ultimate vision for their images. Few people start with perfection and many people spend their lives trying to achieve it. Mastery of the craft takes time and experience and it certainly helps to learn from someone who has mastered their craft and can share their wisdom and offer valuable critique.
I get what you are saying and why you are saying it, but I'm not agreeing with it. There are many many people who are perfectly fine with firing away at whatever camera they have with no rhyme or reason, slapping some filters on the photos, and it makes them perfectly happy with no further desire to "learn and master the craft". You may not like those images, but it makes them perfectly happy. Not everyone pretends that is "art". Hell the majority of instagram users are doing this as a form of personal expression more so than a desire to create "art".
That is definitely not my approach, but I'm not going to pass judgement or get upset by it because others approach photography that way. Good for them. Heck if anything I'm more bothered at how overly sensitive more serious photographers tend to be. I follow Photography blogs on Flipboard, and I laugh reading the comments sections of almost every article at the critical comments that almost always pour into any post no matter how good the pictures linked are.