"armpit stains" lol, how fat are you that you are going to sweat so much biking a small 3.5 miles to work, one way? Even if you are that fat, all the more reason to get off your car seat and onto a bike.
For the record, I do not bike to work to save money. YES, it DOES save me money, but I started doing it everyday since it makes me feel so incredibly good all day long at work. I find days I don't bike, such as to run errands, I feel incredibly sluggish. Plus, I'd like to lose some of my modest post high school weight and biking is my best option, given that I have two kids and other time is limited. Biking simply is exercise traded for commuting time. Yes, I do lose some time because it takes longer to bike. However, I am getting better at it and you gain time by parking right in front of your building instead of way out on the parking lot, it's actually quite convenient.
As for whiners who say they can't, I would like to note that I am the ONLY person in my entire 6 story suburban office building who I have ever seen park at our bike racks. If I can do it in this kind of isolation, you can for sure do it. I choose paths that are mostly residential and the one street I have to ride on is newer and has bike lanes on both sides, so I rarely feel unsafe.