Value of Python is not in Python but in the work of other 1st class people that you can use for free. Just go to GitHub and download all the stuff you need. Not to mention thousands of free articles with strategy ideas on Medium.com that are all written in Python. You won't get that level of quality and quantity in Easy Language, C# or C++ or any other language.
Python is used for prototyping trading systems, because its quick and easy to learn. That diagram you made would be around x20 lines of code in Python and it wouldn't be much different to natural English language you already speak. Python was specifically designed to be easy to learn. Any average person can pick it up in a week or two.
'Slow' trading systems, that work on x2 minute bars or longer can be written in Python. Only if one is into High Frequency Trading he might need C++ or FPGA.
That diagram you made probably took you a week, including idea creation. If you are human you might have, say x10 such ideas. With Python you can use other people's work to assemble data mining software that will automatically find strategies. So you'll get working and backtested strategies from a firehouse, like x100s of them. You'll never have to worry about finding a new strategy again.
You see, your tool creates mindset limitation. You think that the only way is to grind at manually finding strategies. While with a different tool you can go unlimited and have as many strategies as you like, all backtested to your exact desired criteria.
You can check Jacob Amaral on YouTube. He is using data mining for strategies and currently trades with his own money and money from clients a portfolio of x37 strategies on futures. And he had been doing it for around x5 years, maybe longer. All of these strategies were data mined, he never coded any of them and every months he just replaces 2 - 4 of them. He's using C#, his choice, but Python would be much less work.