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."
That's not the original maker being ripped off, that's the buyers being ripped off because they aren't getting the "real Viagra" that they thought they were. And that's true even without monopoly trademarksit's called fraud.
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.
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."
" is not sufficient for promoting an opinion to a fact. And the claim that there is a free market in drug development, when people who patent and submit to the FDA can use force against those who ignore the patents and/or the agency, is just plain false. The mafia claim that anyone is free to do business without paying protection money, too... let me know how they do.