It's a social photography platform. You choose who you want to follow and therefore you choose what you see in your news feed. I guess you aren't following the right people if the Instagram photos that you see annoy you. Photography should be ubiquitous, to document a certain moment. Instagram excels in that aspect very well. I honestly can't thank Instagram enough because every now and then whenever I scroll back to my older feeds I think to myself "Hey, I went to all these places before?" & "Whoa, I wish I was still at this place enjoying the moment/food/etc". Most of which would not get documented if it weren't because of Instagram. Of course, I do agree with you that the majority of the users take poor photos. But it applies to even DSLR users, who call themselves pro just because they own a DSLR.

Photography is an art, but photography holds a stronger value than that which is the power of documentation. Your comment on how Instagram users take poor photos is very vague in my opinion. It basically applies to all photographers not only Instagram users.