It makes sense if it's directed at people who naturally have, or have been raised to have these qualities. In which case- it's like the phrase: 'Know thyself.' If you have been raised to be polite and let others go first- it's going to feel rude to push ahead. If on the other hand, you haven't been taught manners and courtesy and to respect others- you quite likely won't feel bad about shoving everyone else out the way!
It depends on who we are but yeah- going against the grain- as it were for personal protection or gain doesn't always sit well. On the other hand- you can get sick of going through life as a mug. So, it's plain stupidity to say- always be the one to do extra for work or other people if it is just becoming expected of you and/or not appreciated. Sometimes I think you need to be a bit cynical to spot that everyone is exploiting you because they think you're nice/weak. If a cat bites you and you give it food- it will keep biting you! Learned behaviour. Humans are the same. If you work overtime to get your more than reasonable workload done, your workload will continue to be unreasonable!
I agree with some of those statements but certainly not all.