You can't simply assert that. There is nothing to stop companies making drugs and foregoing patents right now. Feel free to point me to them - otherwise lets limit ourselves to the real world.
I can't tell whether or not you're joking. In the real world, people doing business as government threaten everyone who doesn't respect their monopoly constructs (patents and regulations).
You have put forward nothing more than an opinion that pharmaceutical development requires patents, and it is an opinion that at least one person with professional experience in the field explicitly rebuts.
I'm not joking. Even the person you linked to assumed that trademarks ( the ability to sell under their own name) were needed. Imagine a world where anyone can make a drug and call it Viagra - even if they don't copy the real Viagra, the original maker is being ripped off as the sales of that "Viagra" are actually sales that are intended for their "Viagra."
So you see, trademarks and patents are needed
But its a free market. If anyone wants to try to develop a drug without bothering to have it patented and sell it without bothering to have a trademark, let me know how they do.