Why shouldn't anyone be able to download the game some indie studio bet the farm on and is selling DRM-free for $20, and play it for free?
There's a difference between sharing culture and outright ripping people off; if you think this should be prohibited, you aren't really categorically against copyright, only its current implementation.
You need to take that in perspective. Someone legally purchased the game, and then shared it with someone else. It is the exact same thing people would do with cassette taps 2 decades ago, when the RIAA decried mix tapes would kill music. 2 decades later, that industry is bigger than ever.
The difference is that one cassette is much more expensive than 15 megabytes of magnetic storage, and the gas to go from a friends house to let you copy their tape is much more expensive than the electricity and internet bills to transfer the data.
But it is such a common misconception that it is stealing - it is duplicating bits of data on magnetic storage that, by nature of the physical properties of the device, are extremely easy to replicate.
Yes, it is "hard" to understand the concept that once released, the content is no longer under the control of the creator. But defying the physics of physical storage only causes what we have now - big corporate lobbies are pushing to destroy all personal privacy to make sure no one uses the inherent properties of the technology developed in ways they don't desire.
And that will destroy the internet and society at large if left unchecked. You can't take away personal privacy and expect anything less than collapse. The only solution is to accept the reality that digital content is infinitely reproducible for free, and go from there. The old brick and mortar model just does not work.
There's a difference between sharing culture and outright ripping people off; if you think this should be prohibited, you aren't really categorically against copyright, only its current implementation.