Gary .... I don't personally use Beetle Spins, but I do have the grubs & components to DIY one, in the event I think that type of bait would work better, under the conditions I'm faced with or if I need to really slow down my presentation.
Now ... that being said - I do use other baits, where a split tail grub, like the traditional Beetle Spin grub, does fit the bill. I would also use those style grubs on a jighead. Charley Brewer's Whirly Bee comes to mind, as well. The Whirly Bee has a 2" grub on a 1/8oz head. There's a Lil Whirly Bee, in the 1/16oz size, that uses a 1.5" grub. I can see having both of those sized grubs, and using them on other "heads" as well as the Whirly Bees.
So, no .... Beetle Spins & their style grubs are not mainly for kids. They're for kids of all ages, who like to fish with a time proven style of bait/plastic body.
... cp