Perhaps it’s the inconvenience factor.
We stop whatever it is we’re doing three times a day (and, for many of us, only twice, as we daven mincha and ma’ariv back to back) whereas they stop what they’re doing five times a day.
Personally, it’s all nonsense anyway. I like to think that HKBH is far more interested in the *quality* of our tefillos, rather than the quantity.
The Wolf