There's no reason being a kids' show should have anything to do with the quality or worth of a series. If anything, we owe it to our children to put the very highest quality into everything we make for them.
Doctor Who itself has always been essentially a kids' show; it's accessible to adults as well, but the primary target audience has always been the small child watching fearfully from behind the sofa. The Sarah Jane Adventures was a kids' show just as much as K9 was, and had a very similar format -- a trio of teenagers and their knowledgeable adult mentor investigating alien phenomena and saving the world -- but it was far, far better than K9 in every respect.
Oh, by the way, one of the main conceptual flaws that bugged me about the show was the way so many of the threats just randomly came through Professor Gryffen's Space-Time Manipulator. I kept wondering, why the heck doesn't he just unplug it when he's not using it? We saw in the very first episode how easy it is to shut it down simply by unplugging it from the wall.
LOL, "I don't know what to do, these monsters keep coming in through the open door", "Then close the DAMNED door"
One Day I hope to be the Man my Cat thinks I am
Where are we going? And why are we in this Handbasket?