I don't think the problem lies in their specific contracts, but the way they (in this case DBSK) get treated. A shitty contract is a shitty contract, but if you have the support from you company behind you even a shitty contract can seem perfectly fine. In this case they seem bound to what seems to be a shitty contract, and caught at an employer that does not give them respect, concern and the humility required in their profession.
Most of us have been employees a long time, we know the importance of employer/employee relationship at a personal level. I am certain it is even more important for them (dbsk) and So Nyuh Shi Dae, in their profession, working even closer to people, spending time from home, long hours etc. As for the girls potentially being in a similar situation (as dbsk), dealing with similar issues is worrying. Not the contracts themselves, but the fact that when they are overworked, when they're struggling, they don't get the proper support from their employer. This of course, is impossible to know for sure.
Employer / employee relationships are one of the most fundamental parts at any job. And having someone on the other side that truly listening to you, taking your opinions, thoughts and personal feelings into account is extremely important. The absolutely toughest thing is when you need some sort of feedback of any sort from up there, and you get nothing back. Long hours, little sleep can be handled, but when you are in a "we/me against them" situation instead of a "we/me and them" situation, things will get a shit load more difficult, because you don't only have to deal with the hardships of your job, but a personal emotional stress too.
I really do hope SM listens and feel concern for SNSD in a proper way as employers. Like with many other things, very little is needed to make a tough situation easier, just as it's as easy to make a tough situation worse. I just want the girls to be happy and emotionally stable.