As I am more of a back end developer, I've written several interfaces using display:table and then the front end developers cleaned it up into "proper" css. This actually worked out as a good separation of duties and sped up development overall. The programmer in me then asks why this human step is needed if the output is equivalent..
I'm thinking that css is largely about encoding semantic data into layouts, because as far as I can tell it takes tremendously longer to do anything in css today than it did with tables in the 90s. And doing things in tables took tremendously longer than using a GUI like Adobe PageMaker in the 80s. We keep going backwards in productivity but there must be some value in the minimalism of how data is described and organized today.
What is wrong to do is use actual HTML <table>/<tr>/<td> tags for layout, because those impart semantic meaning about the structure of the content and should only be used for tabular data.
caniuse.com suggests only IE8+ supported it.
I'm not really a web designer so this isn't really my debate. I'm just pointing out that "HN does it" isn't really a strong argument. Something might be the best available option for some particular task but still not optimal for a whole host of reasons. The point remains <table> tags do carry semantic information so it's useful when possible to restrict them to situations where that semantic information is correct.
There is no such thing as Bootstrap div hell, that is utter nonsense.
If you used Bootstrap 3 seriously you'd also know there were LESS/Sass mixins for grids. No need to use divs with classes if you have that arbitrary dislike for genuinely useful presentational classes.
Reminds me of this comic strip from 12 years ago: http://okcancel.com/comic/98.html
I do love seeing <div class="table"> around the place. Sigh.
This comment made me laugh. From an outsider perspective it looks like div is the new table. The latest fashion in style
They didn't use it for their grid implementation though, and since they have found and documented a lot of very obscure browser compatibility bugs as part of their work, I'd guess they had a good reason for choosing what they did.
E.g. using SuitCSS Grid:
<div class="Grid-cell u-size1of3 u-sm-sizeFull">