Too many people taking things literally.

Saying I've spent most of my life in and around kitchens, the implication is professional kitchens/restaurants. And around professional chefs.

The distinction between thaw and melt, at least in culinary terms, is actually one of food safety. In a professional kitchen, melting is always going to involve the application of heat, where as thawing (or "temping" as it's often said) is the slow and controlled bringing it to refrigerator or room temperature at which time it can be cooked. A thawed item may or may not be safe to eat, but something melted always will be. Take any course on food safety and the range and time food can and cannot be at certain temperatures, and it's clear why there is a difference between these two terms.

As a way to illustrate why culinary terms are sometimes different than scientific ones. Take a tomato. Scientifically a fruit, right? But you wouldn't put it in a fruit salad or fruit juice. It's culinarily a vegetable, even though we know it's technically a "fruit."