While reading through the textbook 'Modern Applied Statistics With S' by Venables and Ripley, I came across the following paragraph detailing the different types of censoring possible when dealing with survival data. Highlighted is a sentence of particular interest. Here we consider a study where individuals are entered randomly (across a fixed time interval), and those individuals for which the event of interest is not observed are censored when the trial is reviewed at some predetermined fixed time. In the text, they list this scenario as one in which the time to censoring $C$ is independent of the event time $T$.
I understand this to be uninformative censoring, but why is the independence of the two random variables $T$ and $C$ for a given individual be a reasonable assumption to make in this instance?