A champ should not be able to blatantly farm that easily with just one Q. Nerfs are very much deserved.
She does xerath levels of Q poke with just as much range WHILE not being slowed AND retaining full mobility throughout its duration. She's supposed to be a zone control mage but can put out massive damage at the same time, has a skill that is AN ENTIRE LANE wide too. Not only that but each Q missile refreshes rylais duration which makes it easier to land all projectiles, keeping enemy slowed through its duration, and only really starting the countdown AFTER the last projectile hit. She just kites away with her long range whenever someone tries to get close, or makes a lane-wide slowing field. they gave her utility and power probably for the fact that her ult does no damage, but they gave her too much of it all with no real weaknesses