I'm not insisting anything. I'm just saying that lack of immediate and full disclosure is essentially crony capitalism where there are the Big Important Companies That Must Be Protected and then there is everybody else, including small startups and private individuals.

It is fundamentally unfair, and sets up a non-level playing field.

(inb4 "critical infrastructure")

I think it is even simpler than that: The big companies that have thousands of customers doing millions of dollars of business on hundreds of thousands of machines need more time to patch because their is much more money / business to be lost. Not giving large companies time to patch would do more harm than good in the end.

It is fundamentally unfair, and is perfectly reasonable.

Why, might I ask, is fairness required? I'll stipulate that you're correct about said fairness although I could dispute that pretty easily

You seem to have twisted my "tell everyone and let the fittest survive and thrive" into some weird Harrison Bergeron thing which is the exact opposite of my point.

To answer your question directly, it is bad because it gives them a massive unfair advantage over their smaller competitors. It favors incumbents versus favoring efficiency.