Interesting read, @Samuele. Thanks for the post. I'm also a 'noob' when it comes to Lambda calc, Rho calc, and other stuff like this.
As you said, its complexity might be contributing to its unpopularity, though I think those who try to tackle this will be heavily rewarded. Like most things in life, the majority of the population looks for the easy way. Those who take the time to learn and do what others aren't willing to will find a tremendous avenue of opportunity. I think you should continue seeking out learning resources and try to become an expert in this area. It sounds like you have the drive, background, and inherent interest to make it happen.
There are already a lot of confusing things that people don't understand when it comes to blockchain technology. I don't think one more feature being adopted (functional programming), will be a dealbreaker. In fact, it seems to be a good fit for that reason.