I've been a Quinn main (literally only played like 2-3 other champs for a few games) over the past year.
I prefer new Quinn to old Quinn... I don't think she is boring to play at all. Her new blind brings back her dueling capabilities and I prefer actually being useful mid/late game instead of being an assassin who absolutely HAS to get a pick or else they are useless.
What did you do with Quinn's ult mid/late game before? You couldn't really split push like new Quinn. You couldn't really ult and attack anyone if they were smart. If the enemy ADC stuck near the enemy support at all times, you'd never get to them. If mid was super bursty with a heavy stun, you couldn't get to them... then you couldn't burst down any tanks so you were basically good for nothing. Couldn't really split push that hard... couldn't team fight at all.
I'm sorry, I loved old Quinn and Valor but she was unpopular for a reason... and that reason is she was bad. She was hella fun to play... But she was weak and useless in most of the metas that have come and gone.
I've jumped 2 divisions in 1 day on new Quinn. I'll take winning with Quinn only being slightly changed over losing more often with old Quinn and not having much fun when behind.