Sentence Correction

According to a recent poll, owning and living in a freestanding house on its own land is still a goal of a
majority of young adults, (like that of earlier generations. )==UNDERLINED

(A) like that of earlier generations
(B) as that for earlier generations
(C) just as earlier generations did
(D) as have earlier generations
(E) as it was of earlier generations

OA=E

I understand why E is correct but I can't see why the other choices are wrong, especially according to the OG explanations.
1.
My understanding is that A is wrong because the goal is shared ( the same), so you can't use like to compare the same goal, which means like can only be used to compare 2 DIFFERENT things, so A is incorrect? HOWEVER, OG said A is wrong because it lacks subject and verb and is not parallel to the main clause. And it seems that this explanation has nothing to do with my understanding. So am I wrong about the usage of LIKE VS AS, with respect to the compared things? But the OG explanation is too vague and what is the exact reason why A is wrong, more specifically?

2.
Also, for B choice, OG provides the same explanation " without subject and verb, is not parallel to the main clause". However, why can we not see THAT FOR EARLIER GENERATIONS as a subject, so this choice just need a verb, not like what the OG says.

3.
C-og thinks its not parallel because of the subject and verb.WHY?
The subjects are not parallel because they are not the compared things? Does that mean for the parallelism, you should make sure the subjects are the same type, e.g. people to people, AND the compared things to be the subjects.
What about the verb? You should only use" to be "in the second clause to match" to be" in the first, like "was" to "is", BUT NOT "did" to "is". So the" to V" is not parallel to "to be"? I don't know what they should be called by terminology, but i refer to verbs like do, have, dance as "to V" and "am, is, are, were, as" as "to be".

4.
OG=the verb have is not parallel to is in the main clause and also does not make sense without a past participle. WHY? Because "have" cannot match "to be", like am/is/are/were? So whenver you see the answer choice contains such a non-to be verb, but in the meantime, the main clause has a "to be" verb, and the answer choice is wrong because the verb forms are not parallel? Also, why it does not make sense without a past participle? Does it mean you should say " have had"? But why? Because the earlier generations started to have this goal in the past? But it also makes sense to say that they have the goal always.

5.
For the correct answer choice E, does it omit "the goal"? So you can omit whatever(subject/verb/object,etc) as long as the meaning is clear, not vague? Can you omit a complete clause? Could you please give me any specific examples?

Can anyone help to clarify my questions, especially verbal experts? Any input will be greatly appreciated! I found a lot of og explanations really confusing and TOO concise. THANKS A LOT!

According to a recent poll, owning and living in a freestanding house on its own land is still a goal of a majority of young adults, like that of earlier generations.

(A) like that of earlier generations
(B) as that for earlier generations
(C) just as earlier generations did
(D) as have earlier generations
(E) as it was of earlier generations

like = SIMLAR TO.
A: Owning and living in a freestanding house on its own land is still a goal...like that of earlier generations.
Here, that seems to be standing in for goal.
Conveyed meaning:
Owning and living in a freestanding house on its own land is still a goal...SIMILAR TO THE GOAL of earlier generations.
Not the intended meaning.
The intended meaning is that the two generation have the SAME goal:
The goal of owning and living in a freestanding house on its own land.
Eliminate A.

Generally, as serves to compare CLAUSES.
B: Owning and living in a freestanding house on its own land is still a goal...as that for earlier generations.
Here, that seems to be standing in for goal.
Implied comparison:
Owning and living in a freestanding house on its own land is still a goal...as the goal for earlier generations [was a goal].
The words in brackets are omitted, but their presence is implied.
This comparison is nonsensical.
Eliminate B.

C: as earlier generations did
Here, it is unclear what earlier generations DID.
Eliminate C.

D: as have earlier generations
Here, it is unclear what earlier generations HAVE.
Eliminate D.

The correct answer is E.

OA: Owning and living in a freestanding house on its own land is still a goal of a majority of young adults, as it was of earlier generations.
Here, it (subject pronoun) serves to refer to owning and living in a freestanding house on its own land (the preceding subject).
Implied comparison:
Owning and living in a freestanding house on its own land is still a goal of a majority of young adults, as owning and living in a freestanding house on its own land was [a goal] of earlier generations.
The words in brackets are omitted, but their presence is implied.