Why does Drupal 7 prefer CSS @import rules to  tags? "Don’t use @import," lots of guys say. 

There are lots of shortcomings of using @import.


Using @import within a stylesheet adds one more roundtrip to the overall download time of the page.
Using @import in IE causes the download order to be altered. This may cause stylesheets to take longer to download, which hinders progress rendering making the page feel slower.


Why does Drupal 7 use it? 

I want to change the @import rules to &lt;link&gt; tags. How can I do this?
Don't use @import to import css files:


  @import is used only in non-CSS aggregation mode. This is done to workaround IE limitation with the number of  tags.


This should explain the reason and how to get rid of it. Any production site should use CSS aggregation, and not have @import.