Eh. The creators of Instagram are getting paid because their customer is really Facebook (or any other large social network that was willing to buy them). I don't have a problem with them making money (though I think their valuation, and Facebook's valuation for that matter are too high by at least three orders of magnitude). The relationship I have with FB (not an Instagram user here) is that they provide me with a valuable service (easy communication with friends I don't see every day) and I give them a certain amount of info about me and the chance to show me an ad or two. (To date I have not clicked on a single FB ad, though they may surprise me one day.) This relationship is fine by me. I don't claim ownership over what they built. Yes, sure the stuff I give them is mine, or as close to it as it can be, and if they say otherwise I am not happy about it, but they built this ecosystem and got virtually everyone I know to join, so they did 99% of the work as I see it. In the end, if I was posting gifs to my own blog, I would produce nearly zero value.
Another way to look at this is that FB's valuation at the time they went IPO was about $50/user. So sure, you can ask them to give you even $40 of that, and sure if you also actively participate say on Reddit, Twitter, Instagram, and LinkedIn, you might own let's say $200-$300 worth of those companies. If you assume that companies like these cannot grow another order of magnitude, you are not really missing out on much.