Tipping is hardly done from one's free will volition and has graduated into an informal bribery.
Giving excuses is one way to indirectly ask for tips (bribery). It's rather unfortunate that such gateman and like many others have viewed tipping as an entitlement.
Favour is often tied to tips, a kind of rub my back while I rub yours.
Many of the people involved are uniformed or security officers, perhaps a form of oppression unless a financial commitment is made.
Informal bribe? It does sounds tricky.
If you have to give a tip to someone with a forceful smile on your face and the other party feeling entitled to it, done openly without any fear of being punished, that is more like a formal bribe 😅.
Truly, this act is more like a culture among uniformed men, it is the reality of the world we live in now. It is either we flow with the tides or get reproached for not falling in line.