Only water, EWR-BOS?
I've seen this too sometimes on CVG-ORD and vv. Flight time, depending on direction, winds, etc. Is usually 45-50 minutes in the air. Which means they have maybe 30 minutes to do the service.
Usually it's not a problem and they do the full cart. Occasionally, I've seen the water/OJ only tray. There were a couple of flights with fairly bad turbulence pretty much the whole time so there was no service - and I don't have a problem if this is the case. But I've also seen a couple of flights on the late night run from ORD, both times completely full ERJs, where they simply said due to the short duration of the flight, they won't be doing a service (both times, I think it was Trans States). If there's turbulence, I understand, but that's pretty unacceptable when it's a smooth flight. Half of the people on the 9pm are sleeping anyway (myself included), and those of us who fly the route frequently know it's not due to the "short duration" as we've seen the full service done most of the time, including on full flights.