Fairness
Only rich people will get it. (no tech has ever done this.)
Better to give money to the poor than science. (family,city,state,nation, has proven local investment beats foreign.)
Bad for society
Dead people make more room for new, other people. (consider going first.)
Run out of resources (live people discover/extract/renew better than dead or nonexistant)
Overpopulation (colonize the seas, solar system, or have a war.)
Stop having kids
Worse wars (nukes are more dangerous than having your first 220 year old person in 2136)
Dictators never die (they die all the time and rarely of age)
Bad for individual
You'll get bored. (your memory isn't that good, or your boredom isn't age related)
You'll have to watch your loved ones die. (so you prefer they watch you?)
You'll live forever in a terrible state. (longevity requires robustness.)
Against gods will (not if he disallows suicide, then it is required.)
More people make more progress faster. I'm glad my parents didn't decide the world would be prettier or work better without me in it. Einstein, Bell, Tesla, Da Vinci etc, still alive and productive would be nice. You're literally asking for others to die out of your fear. The burden should be higher. Have courage. If living longer sucks, we'll know 100 years from now, and decide then. First 220 year old in 2136 unless you know how to make one faster than 1 year per year? And that's if you added 120 years to a 100 year old person starting TODAY.Man up, save your family, save yourself.
Disclaimer: I'm half way done with a book on this topic. Mail me if you're interested. Scivive on the most popular email service.
P.S. Curing aging isn't immortality. You die at 600 on average by accident, and if the parade of imaginary horribles comes true, even earlier.