But the most important issue is that as long as malware can spread through ads (https://en.m.wikipedia.org/wiki/Malvertising), everyone should be blocking all ads.
Or should we just continue consuming people's services and effort while blocking what's sometimes their only revenue stream?
I'd rather not use a service if it has ads and I can't remove them, instead of block them and make everyone else's experience worse.
In fact, not blocking internet advertising is a security risk.
If they get their house in order my opinion may change, but there's currently no business reason for them to change their existing lax systems; no pressure or threat from regulation to hold them liable for what they allow on their advertising networks.