This is just one of the effects of being in the "platform" business and increasing market share/footprint plus consolidation. In the case of twitter, you get some users (SWs/Nudists etc) that negatively impact a different segment of their user base (News outlets etc).
Back then BP/tumblr would have been the platform for SWs, but with those platforms eliminated, Twitter and iG have picked up the slack.
iG went from being a picture sharing platform to a marketing platform, review website, online retail medium, adult service ad platform, comedy channel etc.