Let's do one thing here to help the conversation. Where are we all from and what are the local customs involving tipping. I am from the US, New Yorkto be specific.
Tipping is beyond common and is expected and customary everywhere. Taxi, restaurant, porter, redcap, bellman, doorman to name a few. Limo driver, tour bus driver, car wash guy,parking attendent, all expect a tip.
What is common in your home area?