Trying to consolidate the comments thread on the other post, since its getting long, and is relevant. 

There's no 'proper' solution for the lack of usable alt-tags as I see it - there's just too many posts!. If someone decides to fix these in an appropriate manner (no edit flooding!), does a good job at it, and mentions this question as the reason, I don't see any reason why suggested edits  that fix images on posts shouldn't be accepted. 

I'll personally be adding this to things I fix when I fix other things as well. 

*However* what you're talking about is alt-tags for the keyboard images I think - which [apparently works by default][1]. I'm curious - does <kbd>![Windows Logo Key][2]</kbd> work better? 


  [1]: http://meta.stackexchange.com/questions/232024/alt-text-in-images-in-keyboard-tags#232026
  [2]: https://i.sstatic.net/GIQBX.png "Windows Logo Key"