What would you replace for x and y? Mathematicians study equations in the abstract. x is just a real number. It's not distance, or time, or velocity. Would you rather they say "real_number" everywhere? And then what would you do when the formula has more than 1? "real_number1" vs "real_number2"?
As to your original criticism, I'll wager that more people in this world will understand f(x) = 5x + 3x^2 than will understand rudimentary code, as it is taught a lot more than programming is. I don't mean anything negative when I say this, but the only people I know who complain about math syntax are programmers. By changing these conventions, you are asking all mathematicians, physicists, chemists, most engineers, economists, etc to change. I will wager that over 95% of them will not prefer your style.
Finally, the trouble with replacing f(x) with Y is that the former tells me I'm dealing with a function. The latter does not. In fact, for many mathematicians, y = 5x + 3x^2 is a constraint, not a function.
As to your original criticism, I'll wager that more people in this world will understand f(x) = 5x + 3x^2 than will understand rudimentary code, as it is taught a lot more than programming is. I don't mean anything negative when I say this, but the only people I know who complain about math syntax are programmers. By changing these conventions, you are asking all mathematicians, physicists, chemists, most engineers, economists, etc to change. I will wager that over 95% of them will not prefer your style.
Finally, the trouble with replacing f(x) with Y is that the former tells me I'm dealing with a function. The latter does not. In fact, for many mathematicians, y = 5x + 3x^2 is a constraint, not a function.