I wonder if developers who do this simply don't want to publicly identify and take responsibility for bugs that they introduced earlier. It's easier to just say

I wonder if developers who do this simply don't want to publicly identify and take responsibility for bugs that they introduced earlier. It's easier to just say "bug fixes" then it is to say something like "I overlooked several surprisingly common edge cases in the parser module and have updated it to correctly handle several character sequences that were causing exceptions to be thrown." With automatic updates and vague update notes, anyone who did not directly experience the bug never has to know it existed in the first place and the developer never has to admit it existed in the first place.