How many studios or publishers are still in business under the same name? And how many gamers would actually care? Even in the worst days of Ubisoft's "add DRM until it doesn't work for 50% of legitimate users" approach people still bought their games.

There are many older games that still have an avid fanbase (which can imply potential for a shitstorm).

StarCraft is the exception that proves the rule, and Blizzard did actually release an official no-CD patch. Other than that, what games, and what company would they impact? E.g. my friends still play Total Annihilation, but the company that published it went bankrupt years ago; Gas Powered Games might theoretically be affected by their reputation but they probably don't have the rights to release a patch for Total Annihilation even if they wanted to.