Being able to disable an input is an entirely standard and reasonable thing to be able to do. The TypedInput doesn't do it because we haven't had a need to do it and no-one has asked before.
But we really don't need to be discussing the why's of this.
@BartButenaers if there are other things like this you stumble over, then please do flag them up. And don't assume I read every post on the forum - if you want my input, mention me directly.