you don't need the price to be high in order to receive bitcoin as your salary. if you think the current price is low, then it means that your salary will get you more bitcoins as result compared to when the price is really high. that's the benefit.
That's true but what is the use of holding them for a long time till it reaches to high point, as you will never sell them till the price goes higher and no one knows when exactly it will happen.
well, people holding their coins for a long period of time can have several reasons. the pure investment minded people keep holding till it reaches a certain price level to sell at. others purely use bitcoin as store of value tool to keep their holdings out the reach of governments and banks. and the price going up makes it an extra bonus for them.
People can afford to hold them for a long term only if they have other source of income and bitcoin is pure investment for them but a person whose income is only from bitcoins will not prefer to hold it for long term as he needs money to run his life and take care of his family.
every bit of generated bitcoin should be seen as an extra revenue stream, and not as main income. that's very important to know. you should never fully depend on bitcoin unless you are earning big when you for example run a very profitable service or something.