They don't want the $10/mo student because realistically that student is only going to be a drain on Twitter.
They want the $100/mo "amateur" who has an actual shot at growing to a $1000/mo or beyond tier. If they don't blow up they want that user to stop paying and being a net-drain on Twitter's constrained and expensive (man-hours) resources.
Further they want to price out some bad actors. See cheating differential in free vs. paid games.
Look I disagree strong with Twitter's direction and leadership - but this pricing ain't the hill to die on.