I feel like it would depend on lighting honestly. From the sound of your experience, it would seem like your ride was during the daytime where all those obstacles are easy to see. During well-lit rides too many call outs become redundant and should only be saved for actual danger. During a night ride, where everything is now hard to see, the number of call outs should increase significantly. Still, if they are constantly calling out in a distressed and panicky voice then they should try to relax a bit because distressed call outs put everyone on edge which is even more dangerous than the perceived "danger" that they screamed about.