I'm sure many of us have been in a situation where they've been sad/upset about something. And then someone comes along and tells you that you shouldn't be upset because there are "people out there who have it worse than you".
So what? That means I can't be upset about something that's saddened me? By that logic you're saying nobody in the world can be upset about anything because someone* somewhere* has it worse than them. You lost a family member? Better suck it up and dry your eyes because the guy next door lost 2 family members and so on/so forth.
Yes, my problems may seem miniscule to someone in Gaza, but they are MY problems, relevant to MY life. I am grateful for what i still have & this helps me to anchor myself. But you cannot help how you feel if you're upset. Telling someone to supress their emotions is disrespectful.
EDIT: Holy shit, was not expecting so many people to have opinions on this. Let alone share my own opinions on it. But yes, while many people use it themselves to help keep themselves anchored, if it works for you that's totally fine and im glad you have a method to do that. For those who are missing the point, saying this to another Human in a derogatory or condescending way makes you the asshole; this was my original point.