An adjective and preposition added to is means wasted words, ones that can be saved with stronger verbs. Is applicable to: applies to. Is indicative of: indicates. Is able to: can. To be goes with nouny writing. When you bury a verb in a nominalization, a weak verb like to be often follows it. An action with a strong verb (Rutherford split the atom) becomes a static noun phrase (Rutherford’s splitting of the atom), which then needs a weak verb like was, or maybe led to or resulted in, to solder it to the rest of the sentence.
