Gokhan
Might you be getting confused by patent-ese? 'Preferred' in a patent is a way of narrowing down a claim. It doesn't have any commercial relevance to market choices.
From at quick scoot around Google it looks to me that MoDTC has been around since the mid-60s with RT Vanderbilt leading the way (met them once, very nice people).
At some point the Japanese outfit Asahi Denko (met them too, preferred RTV) got in on the act and established a decent patent position. Between the two, they had a virtual stranglehold on Moly in lubricants; something that was not at all popular particularly with the major AddCo's as it forced them to buy in something they didn't themselves make at huge cost. And even if, as an AddCo, you did buy it, there was a still a sense of fear that you still might get sued if you used it in a pack.
I can speak from experience that there was a great deal of anti-Moly prejudice around at one time. 'It turns oil your black!' was expressed to me more than once by people in the US that frankly should have known better. One of the things I am most proud of as I look back, is how I broke that in-house prejudice and made Moly respectable.
I can still remember the first time I heard about Tri-Nuclear Moly. It was shortly after Paramins (Exxon's AddCo) had merged with Shell to form Infineum. One of my customers had recently had a visit from the newly merged company and they said how bizarre the meeting had been. They had asked for a proposal for an oil program they wanted to run but what they got instead was two proposals pitched by two teams (all in the same room); one 100% Paramins, the other 100% Shell. Not unreasonably my customer said why don't you take the best bits from both companies and give us just one offer; maybe say a high treat of Tri-nuclear Moly and put it with Shellvis VII? At which point the Paramins guys went all wobbly & spluttered out various reasons why this was impossible. Apparently this was because TNM is hopelessly expensive to make!!
Having just had a look at the original patents, I can see why. Yes it is a variant on the dithio-carbamate theme but when I see chemicals I've never heard of whose names I can't pronounce, you know you're dealing with exotics which are going to break the bank. I dare say Infineum sell a lot of this to ExxonMobil (they're a bit stupid that way) but to others....hmmmm...I'm not so sure.
For what it's worth, I think your confidence in TNM is a bit misplaced. I only say that because for a while, I had to breathe the same air with someone who claimed to be one of the prime movers and shakers behind the development of TNM (it was his 'greatest achievement' or so he said). Anyway, said person was truly dead from the neck up, intellectually stunted and a complete knob. If he said something, I would always assume the complete opposite to be true.