CSS's !important was added because of laws about font size for some text
Engineering is doing what you can with what you've actually got. If what you've actually got is an inherited tremendous ball of spaghetti css, a need to change just one thing on the page, and scant prospects for future changes in the area, then it may be good engineering to use "!important" to make your change over a more complex solution. This is in fact the situation I find myself in at work somewhat often, although luckily I can't recall the last time I had to use "!important". But I wouldn't issue a blanket disendorsement of it.