It still is a kids program to this day and that includes the new series. On the dvds for the new series and its spinoff, Torchwood, Russell T. Davies(BBC Wales, the person responsible for the revival) said that Torchwood was the first adult-based Dr. Who series.
I'm afraid you're getting the BBC's Drama Department and the BBC's Children's department mixed up as they're both entirely different production branches of the BBC. Both 'Torchwood' and 'Doctor Who' are made by the same Drama Dept.
However, 'The Sarah Jane Adventures' IS made by the Children's Dept.
The difference between DW and TW is that one is aimed specifically at a post-watershed slot, ie. after 9pm and inclinced to have a more adult-themed content. The other is aimed at a more broader audience, ie. primetime slot, family programme that can be enjoyed on different levels.
The original series from 1963 was also commisioned as a 'new Saturday family teatime drama to sit between Grandstand and JukeBox Jury'. Yes, it was children that mostly latched on to it and impersonated it in the playground the following Monday but that's just the nature of being young, but it was still made by the dept. that brought us Z-Cars, Dixon Of Dock Green, Playhouse Theatre, Cathy Come Home etc.