According to Kemeny and Kurtz, omitting Let on any assignment is a sign of bad programming practice, and only Street Basics allow such horrible habits. The reason: Let distinguishes use of the equal sign (=) for assignment from its use for tests of equality. It’s true that Basic is the only popular modern language that overloads the equal sign to mean both assignment and equality. C uses = for assignment and == for equality. Pascal uses the symbol := for assignment and = for equality. In FORTRAN, = means assignment, and .EQ. means equality.
If you think about it, Let a = 1 is technically accurate. It also lets compilers optimize more efficiently. In other words, this pedantic nonsense makes perfect sense. Fortunately, Microsoft didn’t buy this argument, and neither should you.