[rmetzler]

Grids are used in typesetting for hundreds of years. Using grids is a best practice to enable manageable but aesthetically pleasing designs.

Grids just make it easy to talk about where to put information on the screen. People could bring their own grids, but often it's easier to just reuse what exists. This is especially true for responsive websites which need more than one fixed-size grid.

Also using a classname convention that is established by Bootstrap or any other CSS-Framework helps to switch styling without having to change a lot in the HTML code.

[hiphopyo]

Grids have been used in architecture for thousands of years.

Sure, they might come in handy when drafting your webdesigns in Adobe or whatever, but not in the CSS. Just use your eyes and basic CSS. For true responsive websites, use media queries.

As they say, "perfection is achieved, not when there's nothing left to add, but when there's nothing left to take away".

[baby]

I've done it both ways and it's just faster with grids. When you don't want to spend too much time in the CSS part of your website. Especially for avoiding testing it with multiple browsers, using a framework like BS is really useful.

[hiphopyo]

Good point. Thanks.

[baby]

to expand, it still feels like a hack most of the time, and I must use like 20% of all the package (form styling are very useful though). And I bet most web developers who use BS do that, but it's not really important as BS is really light and you should focus on shipping (and BS helps focusing on things that matter).

[adwf]

Bootstrap 3 is a responsive grid that uses media queries. I can trivially adjust the look of a site on desktop/tablet/mobile, all just by adding a few classes. When you add in the fact that they manage all the cross-browser/platform quirks for you, it's quite a winning proposition to use Bootstrap to start off a new site. You'll certainly end up overriding various colours, margins, etc. but that's the easiest part of CSS anyway.

[hiphopyo]

My point is that you don't need Bootstrap to use media queries. Nor to manage quirks when there are way simpler solutions available on GitHub.

These quirks are becoming less and less over time as well, as new browsers and devices start to follow the same standards, and major players are dropping support for old browsers (ie. Google is no longer supporting old versions of IE).