Why are modern nails (Precise and Fitbone) not weight beairing?

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When I did my research on internal nails, the Guichet nail stood out, because it was said to be weight bearing, which for me was really important (I ended up choosing Dr. Monegal and Fitbone, though).
In this forum I have seen over and over again the fact of the Guichet nail being weightbearing, the single most important reason people are considering Dr. Guichet.
So my question is, why the modern nails like Fitbone and Precise that were developed by talented engineering teams well after the Guichet nail, are not also able to be weight bearing?
Especially, I am wondering, why screws are made out of steel, while that means they might bent with a weight of more than 30 kg per leg,  if it seems easily possible to make them out of Titanium, so they do not bent!?
Of course, Titanium is more expensive, but patients willing to pay 25,000 USD for a pair of nails would easily pay a few hundred bugs more in order to have the nail be weight bearing, don't you think?

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Quote from: cole slaws on April 14, 2017, 04:23:31 AMFrom my not so good research I think the precice 2 was made to be smaller to accomadate people suffering from dwarfism and children. This made the nail thinner (8mm) and it could not be made weightbearing. My bones I much to thin for the standard nail so I have to use precice 2's petite nail.

True! I heared that Guichet nail is much bigger, which of course can lead to more complications like we see in case of Unicorn.
I also found this why Titanium screws might not be a good idea:
https://www.ncbi.nlm.nih.gov/m/pubmed/26966974/