But don't you think it's their site so they could do whatever they want to ?
Like for example, you own a huge plot that could be used for agriculture and you let your neighbors plant and grow fruits and vegetables in them. They also happened to use water from your house and you noticed that the water bills are increasing so you put in some sort of a restriction to reduce the bills by telling they can only use X liters of water daily.
And let's say, some of the neighbors give you some of the fruits and vegetables so you let them use X+1 liters daily.
So naturally the neighbors who got X liters would make a fuss about it but eventually the plot and water belongs to you while only the seeds,plants and fruits belong to the neighbors.
Here, the plot and water is like Twitter's servers,manpower, API and expenses
Plants, fruits and vegetables are your content you post.
So if you can't get enough of it(land and water), the best is to leave that plot and to look for another one right ?
Sure, they can do whatever they want, but everyone else is free to criticize them for doing so and go somewhere else with their time. Limiting the amount of time people can spend on your social media site, when you want as many people as possible looking at ads, is a bad idea.