Yeah, I...really don't understand the concern.
I mean, of course, we don't know HOW the system will work out just yet. But, if it ends up being anything like Tapas or Lezhin -- then again, what is the big deal?
If Webtoons adopts that style, you might just be able to get coins for free playing games or watching ads from the site. Course, they would have to make sure it's available in some ways based on reader locations and make sure ads don't cause possible malware. So you'd be able to support your creators and still do it...for free.
That, and you can just buy the lowest tier for coins as often as you can (meaning, when you have spending money that's not needed to go to important things like bills or food or whatever). I know for Tapas, the lowest buy is 1600 for $1.99, which is not that bad. It's not even a monthly payment either. At least with Tapas and Lezhin, you can just choose when to pay and that's just ONE payment until you decide to pay AGAIN.
Sides, even if you DID pirated off another site, you always risk the possibility of getting a virus from some of these places.
Like...let's wait UNTIL they introduce their coin system to actually see if this is something to be concerned about. Even what I suggested could be wrong in the end, but it's a reasonable speculation because that's what I've seen from some sites. Jumping to conclusions over nothing doesn't really help.
Either way -- if you want QUALITY work, you have to end up paying in some way sooner or later. Like, right off the bat, people who make these comics mostly do it as a hobby. So if it's for free, you can't really complain about the quality. You can give feedback here and there so that they can improve, but you can't complain about what you get in the end. It's free. If you want better quality, the idea is to often pay MORE for that.