The DMCA wasn't, in itself, a bad idea.
You're joking, right? The DMCA was a horrid idea, just like the eternal "copyright extensions" (which should have been unconstitutional as ex post facto law changes anyways) the content cartels have been buying constantly.
Think about it. Mickey Mouse - or at least Steamboat Willie, the cartoon - should have passed into the public domain DECADES ago. Meanwhile, Disney rapes and pillages the public domain with impunity; if you want to make an animated or live-action Snow White, or Beauty and the Beast, or anything else they've already done be prepared for their army of lawyers to start screaming "it's too similar, shut them down" even if you follow the original plotlines of the story/book in question.
What happened was that there was no attempt made to stop companies misusing it
Bullshit. DRM rapes the public domain AND tries to take away the fair-use rights of consumers at the same time.
Under fair use, I have the right to make a backup copy of something I purchased. There are MANY reasons to do this - fire/flood concerns, degradation of the original media (DVD's scratch, tapes wear out, etc), and of course the ever-present Small Children and My Dog That Likes To Chew On Things problems.
Under fair use, I also have the right to space-shift and time-shift content. Broadcast over the airwaves, but I'm out to dinner? No problem. Set a VCR up with a timer, watch it later. Archive it for posterity. Want to convert it for iPod, or PSP, or something else that's portable? I have the right to do so. The next round of "DRM" will be trying to push the so-called "broadcast flag" into the shortly-only-available-variety Digital TV broadcasts, which will require either (a) a recorder that ignores the flag or (b) the goodwill of the broadcaster. This is a fundamental shift that will wholly strip away people's ability to, say, record the sunday Packers game for later because they're busy volunteering as an adult chaperon for a church retreat.
With DRM, I am prevented from exercising my fair-use rights for perfectly legitimate reasons. Prior to the DMCA, if I could figure out a way around it (such as a Macrovision Stripper for VHS), I was able to get my rights back.
After the DMCA, no dice. I committed a "crime" doing what was necessary to exercise my legal right to safeguard what I had purchased.
The DMCA itself was a bad idea. Anyone who says differently needs to be slapped repeatedly.