Fine to not make this change. 
I think the ask here really was for a quick and easy way to highlight text in discussions. Many people (myself included) have taken to using backticks to highlight text because it’s super easy… you don’t even have to press shift, and it’s discoverable on the menu. But it’s not very distinct from the rest of the text in the para.
Bold and italics are also on the menu and also do not stand out very much. Other ways to highlight text inline take more keystrokes. Also they are not prominently documented so also require insider knowledge.
As far as I know these are the best ones:
Button <kbd>Button</kbd>
Green underline <ins>Green underline</ins>
Red strikethrough <del>Red strikethrough</del>
Highlight <mark>Highlight</mark>
Strikethrough <strike>Strikethrough</strike>
For folks who can install plugins, there is the official Discourse BBCode color plugin. And for those who cannot install plugins, @merefield created the Discourse Coloured Text theme component.
I also liked the theme component that converted ==highlight== to highlight, but have lost track of it here on meta.