Why am I limited on older release downloads?

Look,  Adobe is a solid suite of tools, however the rate at which features are dropped (particularly codec support) is absolutely painful to professionals in the contemporary field. 

I was recently given advice to download the 2017 version of Media Encoder as it was more flexible for the, albeit strange, codec I was being forced to use. Whatever, I work in live performance, our media servers are strange. Then I learned that using the CC application, this wasn't so straightforward. I'm given the option to roll back on only one patch?

And perhaps if the option of holistic rollbacks is there, why isn't it more clear?

Why isn't it simpler to access easily-mirrorable distributions of older versions? 

This is software dev 101.

This is why people cancel their subscriptions. Plus all these 'new features' are useless without plugins at this point.