People prefer the easier option because it feels safer and it usually involves less work.
Email is an easy option that obviates the need to speak to someone directly.
In some cases, the easier route works better, is more practical, innovative and strategic. But if you want to get it done right, express an emotion, reiterate seriousness, and prevent backlash it’s always best to face the problem directly.
Why go half-ass if going all in (which is what we used to do anyway) produces a better result in the long-run?
No risk, no reward. Take traditional action (i.e. use your voice) when it’s needed most.