node id attribute not consistent with core

Maybe I'm missing a new theming convention, but omega output its own custom id attribute for node wrapper which is not the same as core. I found that issue the hard way (thanks git bisect!) when upgrading my templates from an old version of omega.

core outputs: <div id="node-1" ...
omega outputs: <div id="node-article-1" ...

In other words, omega adds the node type in the node id attribute. I don't find it very useful since 'node-nid' is unique anyways, so adding the type is not necessary to ensure uniqueness. the node type is available in the class attribute if necessary. why this new convention?