Because we already have some government funded open source run by academics, so that is a grounded approximation of how well or poorly it could look like.
I don't know where you live, but I hope OpenSSL is not developed like the roads I drive on. That's not some grand aspiration.
I think the thing about academic open source is that the government is not "funding open source" -- they're funding research, and all the incentives and measurements and funding criteria are set up (give-or-take) to drive towards "better research". Any open source software produced is a by-product. A hypothetical "government funded open source" would hopefully have criteria and incentives that drive towards better software...
I don't know where you live, but I hope OpenSSL is not developed like the roads I drive on. That's not some grand aspiration.