There's a reason they did that. Noddy and Jim wrote all the songs and live very comfortably off royalties just from their Christmas song alone and retired from Slade in 92. Dave and Don wrote nothing and were broke so they kept it going. I don't blame them either...if I were broke but owned a marketable name like Slade, I'd do it in a heartbeat. Most people would. Easy to be a purist when you're not in that situation.
A man's gotta eat.