My co-worker lectured me on rudeness of a large tip

[Not Me]

60. I have never worked in a tip bearing job,

but have many family members and friends who do, and I know how much of a difference this makes.
20% is a starting point for us.

I also have a friend, who a few times a year, will tip *extravagantly* (his term) for someone who goes far out of their way.
I am talking like 100%+ tip. He is not wealthy, and it might mean he has to cut back a little that month, but he says it does his heart good.

We recently took our first real vacation in a long time to Mexico. The hotel was all inclusive and we spent very little of what we had budgeted for the trip. On the last day, I realized that the housekeeper (who had done an outstanding job) was there all 7 days, I guess without a day off. She was working the floor, and was likely holding our room until after we vacated. I called her down, and thanked her and gave her $200USD. Tears began to roll down her cheeks, and must have said thank you a thousand times.
As my friend Tom says, it does your heart good.

(edit typo)