Rule 14.4 and the explanation is not enough to understand why

[xiangke]

MISRA C 2012 guideline says:
Strong typing requires the controlling expression of an if statement or iteration-statement to have
essentially Boolean type.

For example:
typedef unsigned short tudtKalEvents;
#define udtSTOP_EVENT (tudtKalEvents)0x0001;

Code:

if(udtEvents & (tudtKalEvents) udtSTOP_EVENT)
  {
        vidStop();
  }

I think the code is ok, I use the & statement as the conditional expression. As we know, the value is not equal to zero, the condition shall be judged to be true,
why We must use the boolean type?