Another reason is that the output impedance of transistors are very much smaller if minimal length are used, resulting in low gains. Short channel effects will also increase the complexity of the design.
But still, matching forms the most important consideration. It's one thing to design a circuit to write a paper, where you only need one working chip. But for a chip in production, you usually design for 3 to 5 sigma, in which you will find that even designing twice minimal length is often a luxury.