Why Don't We Have Col-xs-offset-* Classes In Bootstrap-3?

I read in twitter bootstrap-3 docs that it doesn't support col-xs-offset-* classes. This doesn't seem in line with mobile first. Is there a good reason for it? I thought they could

Solution 1:

3.0.1 (released 10/29 http://blog.getbootstrap.com/2013/10/29/bootstrap-3-0-1-released/) does have the col-xs-offset-* classes..

https://github.com/twbs/bootstrap/issues/9689