Here's why:
* Linking verbs connect a subject to a subject complement, which describes or renames the subject.
* Subject complements can be adjectives, nouns, or pronouns.
* In this case, "taste" is intended to be a linking verb, but there's no subject complement following it.
To correct the sentence, you need to add the subject that is being described as "hot and spicy."
For example:
* We all agreed that the chili tasted very hot and spicy. (Here, "chili" is the subject complement describing "taste.")
* We all agreed that the food tasted very hot and spicy. (Here, "food" is the subject complement.)
In these examples, "tasted" acts as the linking verb, connecting the subject "chili" or "food" to the subject complement "hot and spicy."