Then another company get another million to develop same or similiar thing.
Why it is not a required that if you get taxpayers' money, the results should be available for free to everyone, let's say after 12 months of grace perioid ??
Probably depends on the development in question, but in general the ability to resell something to someone else changes the calculations for contract work. If you want me to develop something and then own it is not the same deal as me developing something that I get to sell to someone else, too.
Some might also consider it undermining their own industry. Instead of building up software companies, it is essentially the government building a huge software department.
Especially if that industry has evolved into suckling at the government's teat. Taxpayer milk is the sweetest milk.
You might point out that increasing the output of the sun in the real world actually result in a scorched, uninhabitable earth, and that also that's not how any of this works but hey, no analogy is perfect. And this one is plenty good enough to convince voters.
That money isn't disappearing, it goes to the company but also to its employees.
They then return it to the economy.
What you're suggesting is that the tax payers spend their money and get nothing in return - it's corporate socialism.