Generally, I try to allow an hour to check bags and go through security so what time I get there depends on whether I have to park and shuttle or whether I'm being dropped of and anticipated traffic. 2 hours is not unreasonable at BDL if you're flying at a busy time although certainly allows for those that get delayed in traffic and have other delays before getting to the terminal. Here's how I would figure it - allowing for no extra time:
Flight departure time 10AM
This flight could start boarding at probably 9:35
Want to be checking bags by 8:45
Need to be parking car 8:25
Need to leave for the airport by 8AM
Now this has very little wiggle room, so I would probably leave for the airport at 7:30 -7:45. If everthing went great, I would probably be at gate before 9AM. If time allows, I'd rather hang at the gate for an hour, then stress about not being there in time.
FWIW a few years ago, DH, DD and I were flying out of BDL. DH dropped off DD and I and we checked bags and were through security and to the gate in less than 20 minutes DH, when parking the car, had a slight delay with the shuttle bus, then got to the terminal and was in line for over 45 minutes getting through security. We kept calling him saying, the plane is here, they're boarding, we're boarding, it's take off time, are you through yet???, can't you try to cut ahead and just explain your plane is leaving!!!!

THey actually held the plane for over 20 minutes because well over half the passengers were not at the gate by take off time.
My guess is they suggest 2 hours to allow for all the possible places you could be delayed.