My explanation to your questions will focus on the what called as correct and healthy corporate cooperation.
Prolific needs to protect them self's from all those counterfeit parts.
1) Looses money from those.
2) Their work it must be patented, and so they have to protect it.
Secondly, needs to protect their own customers, that are brand-names recognizable in the market.
Who they invest their money on buying the technology made by Prolific ,
and resale it with their own products. ( As part of their own products )
And even the software it self ( Driver) it is part of the Prolific property.
The driver is very well made, and has even the option to change the COM port number ,
so the device to become compatible with any communication software settings,
and it does that with out even rebooting windows.
In my eyes they do well about protecting them self's,
because they have one healthy hardware and software solution,
that it can be trusted by their corporate partners, and there is an warranty,
that the End User will get something that really works and be happy with it.
We had many conversations in this forum, about how to protect our own work,
when it comes to the point our ideas to turn in to products.
And it turned out that just the paper work its so costly,
and that is very difficult for a single person to handle the costs.
And I think that is also our obligation to protect the work of the others.
If we like to be called as healthy thinking persons.