If the usage of ad blockers increases, you can bet that those not using ad blockers will be squeezed and exploited and have a thousand popups and intrusive ads thrown at them in order for the sites to recoup the lost money.
So those using ad blockers are making the web worse for everyone.
They are doing that already, they are maximizing the amount of ads they can shove down user's throats. This is nothing new and ad-blocking didn't change that. You'd think adverstiser would understand by now the reason why people use adblocker...
You're assuming that 'good behavior' of users should somehow stay the hand of marketing companies. It ought not. A good marketing company will do everything to extract full value insofar as it is harmonious to business goals -- ad blocker or not, the search for the perfect recipe of ad delivery will march on.
How is it making the web worse for people using adblockers? Because they are a subset of "everyone"