Yes, Excel is surprisingly powerful. It's also surprisingly cumbersome; you have to fight with it too much. Every time I give in to the "just do it in Excel" impulse, I waste many hours before I get disgusted, throw away my efforts, and start over in a real programming language.
On a recent project, I needed some data reduction, smoothing, and publication-quality graphs. Perfect for Excel, right? Wrong! Couldn't get decent-looking graphs out of it. In the end, it was easier to download a graphing package for Python (MatPlotLib), figure out how to use it, recode everything -- and get exactly the output I wanted.
I've been programming since 1966. I've used Fortran, PL/I, many flavors of assembly code, Pascal, Lisp, APL, C, C++, VB, Java, Python, Maple, etc. I can probably make Excel do whatever I want. Hell, I can probably make a Turing Machine do what I want. But it's not worth the hassle.