The BBC is remaking
The Day of the Triffids The problem is the fundamentals here - it's not the inevitable yoof characters they'll impose that'll kill it. What will kill it is the inability of the BBC to deliver intelligent drama any more. They won't be able to deliver the science, they won't be able to deliver the bleakness, they won't be able to deliver the misguided bigotry and most importantly they won't be able to deliver the ending.
Triffids is not about 6 foot plants with stinging whips, it's about the decline of authority, the natural unpleasantness of the human race in extremis, and the need for everyone to think for themselves.
I'm betting the BBC right now are going "Ooh, low budget popular SF which we could resurrect for a cheap prime-time 'Dr Who Lite' series". This will fail dismally, with people laughing about "that shit TV show with the oh so scary plastic plants"