This is absolutely nonsense ...
Your statistics say absolutely nothing in the state in which you want to present them. And your misconception on the "nonsense" of a development with something other than renpy is bullshit. That said, you can think what you want, but if you could avoid trying to induce false ideas in others it is better.
Your statistics do not indicate the reason for using the filter.
- It could be bad knowledge on the field ....
There are potentially people who have been told exactly the same kind of bullshit that you are saying and who have assumed, for example, that pure VNs are well done under renpy and that's it. And if he came across a bad sandbox game under unity one day accentuating his preconceptions. And we have a guy who filters by choosing renpy but who, if we gave him a good VN done with unity, would appreciate it just as much as if it were done with renpy.
- Or a very good knowledge of renpy which would allow them to cheat more easily than under unity and if he regularly fell on games which require hacking the stats because potentially badly done, he will stay on what he knows.
We could find many more I imagine ...
It doesn't take recursion into account, personally I don't use filters, I don't have a strong preference but it can happen that one day I want to sort with this filter for any reason and it will enter your stats while as said above I have no preference ...
The same goes for people who might have filtered out by choosing renpy one day and unity another day, for whatever reason. The first goes into your stats and makes them go up and the other doesn't necessarily go into it depending on how it's done
It does not take into account all those who do not use the filters and therefore limits this idea preferably to a group whose size we do not know.
And I doubt that those who work on this forum are going to waste their time doing stats readings with rigor and multiple conditions, just for you or a small group of people.
Is it easier to produce a game under renpy than under unity or rpgm or whatever? Not necessarily...
A person who knows how to program correctly in javascript or C # will potentially have an easier time producing his game under unity than under renpy if iits not just the variable / condition .
Someone with a lot of experience with rpgm is going to produce easily with rpgm ofcourse.
And so on.
If we start from zero indeed for a VN without a displacement system on map type rpgm or combat type rpgm, then yes renpy can be easier. This is also why this is what we see the most.
Does that make using anything other than renpy nonsense ... no.
It is a choice, which can take into account many other aspects.
The person can decide to learn to produce a game under unity, learn javascript for example, learn the interface etc ... and make a very good game, only because it gives him more possibilities for the future (game 3d etc ...)
And also a person who needs a combat / inventory / movement system on map etc ... will surely choose rpgm because everything is already integrated.
And again there is a lot of possibility that leads to the choice made by the developers. So nonsense ... Maybe for you but ... who cares.