I agree that generic tags seem odd, but in this case for example, they are useful if you are looking for say: cars or trucks or vans, in a more concise way. It's a similar case to food.
The real answer is to have tag hierarchies with inheritance, but that's not going to happen any time soon (probably ever), so extra tags and implications are what we have that work.
I wouldn't suggest we start a tag for WordNet's 'entity' , since that's so generic as to be completely useless. Something at the level of vehicle still seems to be valuable enough to me to keep.