What a lot of people in the reviews don't mention is the role that Jimmy John's fills in a college town like Kent. JJ's is open until 4am on the weekends. The only other restaurants in the city still open after 10pm are insomnia cookies and Tbell.
Most of my trips to Jimmy Johns were after late night study sessions or work shifts when I was exhausted and hungry. The staff and I both know what we're here for. I have a short exchange with them consisting of mostly grunting and pointing. I wait 2 minutes or less while extremely loud music plays, both keeping me awake and making me want to leave faster. Then I'm on my way home to eat the certainly edible food as quickly as possible so I can pass out.
Also, it's no secret that there is a lot of drinking on the weekends in Kent. JJ's delivery option keeps drunk students off the road and it's quicker than ordering a pizza.
It's not great food, but it does fill an important niche that is sorely lacking in options in Kent.