... many of you who have created 3D gaming engines and are qualified to make such statements ... right?

It doesn't matter whether you are buying the product or not - when there's a lot of objects and a large FoV as well as a large view distance, performance will suffer. You don't get to optimize yourself out of that.
Trust me I know how hard develop code is, in fact you would be surprised that someone behind this keyboard has a knowledge of what it takes to create something from nothing with a few guys. But don't even tell me this is worth 30 euros because if you keep telling me this and keep offending my logic and intelligence then I am not gonna buy this ever.
Create software is hard, improve it can be a headache, debug it double headache, but don't sell my the idea that 30 bucks is the fair price because that's not true.
By the way
It doesn't matter whether you are buying the product or not
Really!?. Thats a good way to improve sales!