I think you mean DMA, not DMCA. DMCA mostly protects copyright holders. DMA is about protecting users and competitors from platform lock-in. Bending for Apple would just make that lock-in harder to challenge.
DMCA provides some rather important protection for service providers (including small-scale services like web forums, not just ISPs and web hosts) - it makes them not liable for copyright violations by their users, so long as they take down infringing content upon receipt of a DMCA notice.
Precisely. What it replaced was rightsholders suing web services (like a forum or web host) as a first resort, which was a much more cumbersome and painful process for all parties.
> If it was more painful for the suing party, it was a good thing.
It's a lot easier for a large plaintiff - like a record label, a movie studio, or a software publisher - to file a lawsuit than it is for a small defendant like a web site operator to defend against one.