The memes and clips do encourage a sense of nostalgia but the reason I think it's blown back up so much online is because the show is a visual, cultural snapshot into our British Y2K childhood.
It gave our generation a better understanding of what being in care was like for those who hadn't experienced it. They weren't just 'naughty children' but born into an unfortunate situation.
As cheesy as it might sound, our generation has grown up with Tracy Beaker – some of us now have children and she now has a child, too. Worrying about finances, wondering about how they'll cope, worrying about their child's wellbeing – they are universal themes for most.