These deals were indeed standard back then. They were also a way to enslave artists. Ten albums is more than the average artists career (the average life span of a rappers career back then were three years). This meant that aspiring artists were offered a deal on unfavorable terms and since they weren't famous yet, they had to take it, since all major labels offered these deals to new artists. Owing the label ten albums meant that they couldn't renegotiate the terms of their deals before they delivered these ten albums. And if the artists complained or tried to renegotiate, or asked about what happened to their royalties, the label could simply shelve their projects, which effectively blackballed them, because their label wasn't putting out their projects and other labels couldn't sign them, or had to buy out their contract for large sums of money, since the artists still owed their label x amounts of albums.
These types of deals were one among the many shady practices labels employed to exploit artists. People defending this are either retarded or working for a record label.