Problem is, Microsoft and other software vendors don't want you to learn too much about their cars (otherwise you might notice there are better models), they only want you to continue buying their cars, for which they continuously do everything to give you the impression their car is really easy to handle, so easy that you don't need to learn anything.

Of course you can't since you can't see under the bonnet, except for what an incomplete user manual tells you.

Hence the issue with "closed source".