People have different tastes, so if someone likes a dish slightly saltier than the chef thought it should be, it is arrogant of the chef to refuse to provide salt at the table. He (usually he) may be the professional, but it's still a matter of opinion and taste buds. Of course, you should taste food before adding any further seasoning, but having tasted it, it's no one else's business if you do add some.
Avocados are terrifically good for you, but surprisingly high in calories for a fruit. Still, as a rule, you eat only half a one at a time. Packed with vitamins and unsaturated fats, they are even good for stroke and heart patients. Great weaning food for babies too. By the way, as soon as avocados are ripe, they fall off the tree. Consequently, they must be picked before they ripen, but will ripen quite naturally – and utterly deliciously – left in a slightly warm place.