What is important and what is not? I think this is always a question of your point of view.
Yes emergency items are in case you need them more important than a waste bin. But if you visually search for them on the standard-map in the moment you need them you waste a lot of time anyway.
So having them in the data enables "you" to produce a map that shows these things prominent and hides those things that are not important for that purpose.
If you feel that it should be added as an icon to your preferred map-style it is better to propose it there than here, where it is more the issues in the database that can be worked on.
For the "standard" Carto-style these would be the pages to look at
https://github.com/openstreetmap-carto/openstreetmap-carto
https://github.com/openstreetmap-carto/openstreetmap-carto/issues