I have never seen it, but a quick look round the interent shows it runs for only 1 hour and 45 minutes, but more importantly has 3 acts.
So I guess with any 3 act play is, where do you have the interval.
Two intervals (between each act) would be overkill, but having only one interval leaves you the decision of having it after the first act or the second act.
So maybe it was decided on no interval (to keep the suspence going).
As we can all sit in the cinema for 2 hours without needing a break maybe sitting in the theatre for less than that is not seen as a problem.