What 's "on"?
What's "on" at the end of the sentence?
Sponging off the kindness of strangers to further our own selfish travel goals is just not on!
It's from this passage.
So when Western people, with all the privileges we hold, are found 'begpacking' on the streets of developing countries, it can leave a sour taste. Tourism is a vital source of income in many countries; we should travel in such a way that maximizes the benefits for local people and businesses. Sponging off the kindness of strangers to further our own selfish travel goals is just not on! If you can't afford to travel, stay at home until you earn enough money to do it ethically.
The original article is ://www.boredpanda.com/begpackers-tourists-travel-begging-locals-money/?utm_source=classic.italki&utm_medium=referral&utm_campaign=organic
Thank you very much.