There is no sensible reason to question the quality of cricket. ROW games were tests when played, and only downgraded later. Both ROW and WSC had the world's two top sides. WSC reduces the test sides to B teams for a while, opening up an extra gulf in quality. Plus a team of the world's top players, including the RSA players who weren't playing tests. It's leagues above test cricket of its era in quality.
Players had more reason to be motivated than tests for WSC in particular. It was higher profile, had better competition and financial motivation. Multiple players stated it was the most competitive cricket they had ever played, but I've never heard of anyone indicating anything to the contrary. The RSA players should have been even more motivated to perform than most, it being their only opportunity at top levels. This applies to some extent to the AUS players with uncertainty over bans as well.
Players had more reason to be motivated than tests for WSC in particular. It was higher profile, had better competition and financial motivation. Multiple players stated it was the most competitive cricket they had ever played, but I've never heard of anyone indicating anything to the contrary. The RSA players should have been even more motivated to perform than most, it being their only opportunity at top levels. This applies to some extent to the AUS players with uncertainty over bans as well.