Sheffield's trams are actually a lot of use, now that they are run commercially by Stagecoach they have been making money for the past 5 years. The system was originally designed and built to serve the high rise tower blocks in Park Grange, as well as those in Hillsborough. However, over time these have been demolished (tram services were halted when the last block at Park Grange was blown up), and the system has needed to refocus. It doesn't just take people to Meadowhall...it takes people from Meadowhall to the suburbs along that line, the city centre, provides a valuable link from teh University to the train station, and also a valuable park and ride site on the outskirts of the city for the city centre.
In fact, Sheffield is probably the least "pointless" system of them all, if you are going along those lines...Nottingham people said was pointless because it served a train route (bear with me, I know it's not a pointless line at all, because I live there...but you can see why it might be thought of as pointless), Croydon seems pointless as it has no park and ride facilities to take traffic off the roads (yet is successful in transporting people around the suburbs (i've visited). At least Sheffield, in its inception, had a clearly defined "point" of getting people into the city from the suburbs as well as reducing local pollution (Sheffield after bus deregulation was chaos).
Meadowhall is quite nice to visit...or visit MG Sharps in Attercliffe for railway modelling supplies (Attercliffe tram stop), so maybe it is worth the effort.
Regards
Dave