I pretty much do? I definitely have some strong personal biases toward particular instruments and not others and I would push for those. Asking a kid to choose a music instrument yields a decision every bit as informed as rolling a dice. Why bother?
Surely the kid can choose an instrument on the basis of the one that they like the sound of or even what seems 'cool'. They will probably have more motivation to study something that they have chosen themselves even if it is for fairly superficial reasons.
It's not like there is an objective way to choose a "better" instrument anyway since half of the fun is playing with others who use different instruments.
So why not, as a parent, present a set of options that seem reasonable to you and have them choose amongst those? i.e. you can play one of e.g. {piano, violin, clarinet}. When the child is better informed, they can choose for themselves. Until that point comes though, asking children to make arbitrary choices, particularly ones that affect their development, seems silly to me.
Python and Java are equivalent in the sense that both a Turing Complete. Is there a similar equivalence between all musical instruments which makes choosing one over another a purely arbitrary decision? I don't know but I suspect not. A pair of bongos seems to have much less to offer as an instructional vehicle for learning about music than, say, a piano.
EDIT: Setting aside the above argument for a second, there are practical considerations too that make the choice of musical instrument a non-arbitrary decision. For example: the cost of the instrument, its portability (important if the band decides to tour) and of course the availability of instruction.
I don't know if your comment is a troll or if you're simply dim. I assume troll. Still, I'll bite:
The relationship between a parent and child is not a democratic one. As a parent you have a responsibility to make choices for your child until they can make them for themselves. I do not agree with letting kids decide which developmental activities they will or will not partake in or how they will do so. Is that clear enough for you, sunshine?