The servant observes that the original group of people have been preserved by the efforts of the Lord. There is still a "root" which "have not perished" (5: 34.) The bloodline remains. The covenant can be renewed with them. While it would require work, the potential for reviving the failed family remains possible.
Despite the potential, the Lord of the vineyard has a more practical objective in mind. There must be actual saved souls, part of the Family of God, for the work of preserving souls to matter. "The tree profiteth me nothing, and the roots thereof profit me nothing so long as it shall bring forth evil fruit." (5: 35.)
They have been preserved to allow for the possibility for a return of covenant Israel. (5: 36.) However, it must result in an actual return, the living tree bringing forth good fruit, children of promise, raised in righteousness, schooled by parents who will raise them to keep the ways of God as His people, for the effort to have been worthwhile. (Id.)
The root, and all the various manner of fruit which sprang from it, have "overrun the roots thereof" and only "evil fruit" was left. (5: 37.) Not just evil fruit, but "much evil fruit" was the result of this long apostasy from the original. (Id.) The overwhelming production of this vile product has overtaken the "root" so that the entire tree appears to "perish" and "it will soon become ripened, that it may be cast into the fire, unless" the Lord does something to alter the course it was following. (Id.)
Christianity failed in its original purpose. No one was being saved when the Lord considered His vineyard. Left to its own, the result would be universal destruction at His coming. He would burn the vineyard and remove all the various Christian offshoots claiming to have originated in the New Testament stock.
This allegory shows the need to separate ourselves from Historic Christianity. If we are part of it, then we are nothing worthy of being preserved. Like them, we should be gathered into bundles and cast into the fire.
When the Lord declared that "they were all wrong" and "that all their creeds were an abomination in his sight" and "that those professors were all corrupt" (JS-H 1: 19) He was confirming the allegory of Zenos and the prophecy of Jacob. This was the condition of the vineyard.
We should view the ambition of being considered part of that "abomination" and "wrong" "corruption" as an unworthy ambition. We are NOT (or at least should not) be part of the Historic Christian tradition. It is riddled with "much evil fruit" and the people who profess their creeds are "all corrupt." Not in the sense that their hearts are vile, but in the sense that they do not comprehend what it means to be part of the Family of God, much less even occupy that association with Him. They are orphans, unconnected with the "living vine." (John 15: 4-6.) Unless they occupy a family relationship with God, they are not His and will be gathered and burned at His coming.