There's another reason to wear cycling specific outerwear. The bright colors. Yes, I know, there are plenty of dark blue, etc, cycling jackets out there, but a bright one, esp with reflective tape is very visible. And for those of us who live in the north with many short days of grey skies, bright means fewer expensive "taxi rides" to the ER. And on my health plans, the deductibles I haven't dipped into have covered the cost of expensive jackets rather easily. I am reminded every time I drive of just how not visible proper attire like brown jackets and slacks are. Blue, black, red and patterns often are no better.
Also, details like 2-way zippers, velcro cuffs on sleeves, long arms that can be pushed up and armpit and back vents make commuting in hills a lot more pleasant. The folks around me after also appreciate it.
Ben