As has been pointed out, there is nothing about Ctrl-Alt-Delete that makes it dangerous in the hands of children. Windows supports per-account security, and it is generally a bad idea to allow unsupervised children to log in under an account that has administrative rights on a PC environment where you are concerned about data, or any scenario that you're unable to repair using the very simple system restore feature. That is a matter of good parenting and is not a technology issue.
Mobile devices like tablets or phones are much more limited purpose, they do not allow the user to do many things, because they have a much narrower scope of functionality. In the hands of a menacing child they are likely to be more inherently bulletproof from a data perspective, but more likely to be dropped or damaged. They are also very difficult to get any level of real work done on, so its best to use the right tool for the job.
From a perspective of running task manager, killing specific processes, etc. there is not much difference in available features across Windows, OSX, or any other desktop OS, while mobile OSes typically have no need to allow this level of control.