Dickinson's unusual punctuation and rhyme ("near-rhyme" or "slant-rhyme," in which the rhymes are inexact) are an integral part of her means of expression. Look, for instance, at
The Soul selects her own Society—
Then—shuts the Door—
To her divine Majority—
Present no more—
The dashes give the impression of interrupted thoughts, as if the speaker is stopping and starting, hesitating at drawing the conclusion of isolation that is the poem's theme. Removing the dashes and replacing them with more conventional punctuation would destroy this impression. Much of her poetry gives one a sense of a soul feeling its way tentatively, partly because the original and unconventional ideas expressed by the speaker would not be accepted by an outside, critical world:
Because I could not stop for death—
He kindly stopped for me—
The Carriage held but just Ourselves—
The arresting idea of Death as a suitor is expressed as if the speaker herself feels some reservation about it, unsure if this is really what she wishes but ultimately accepting it. The last stanza of "Because I could not stop" has an almost free-fall effect after the first line:
Since then—'tis Centuries—and yet
Feels shorter than the Day
I first surmised the Horses' Heads
Were toward Eternity—
The lack of punctuation stops at the ends of the first three lines, in keeping with the sense of time flying by in the eternity of death, of feeling "shorter than the day."
These elements, including her irregular capitalization, give a dreamlike effect which reinforces one's sense of the speaker already being in another world, as is explicitly the case in "Because I could not stop," but is Dickinson's intention in many of her other poems as well. The off-rhymes, as well, are a feature of this other-worldly expression in which exactitude is unnecessary and even wrong. A further point needs to be made about the rhymes. Several decades before Dickinson, Byron in Don Juan made use of near-rhymes or approximate rhymes to great effect. Yet few, if any, critics or editors ever thought there was anything wrong with this. For example:
And in thy stead I've got a deal of judgement,
Though heaven knows how it ever found a lodgement.
Couplets of this sort occur throughout Don Juan and are not unusual. It's also true that even as late as the early eighteenth-century, we see vestiges of the older vowel pronunciations in English which, for example, caused the following still to rhyme in Pope's The Rape of the Lock:
Than, issuing forth, the rival of his beams
Launch'd on the bosom of the silver Thames.
Add to these examples the use of "eye rhyme" by poets of all ages, and the question arises as to why early editors did find fault with the procedures used by Dickinson. It may have been the result of at least an unconscious criticism, or a kind of redirected (or misdirected) judgment, of the original and unconventional ideas in her verse. Or it may have even been a form of gender discrimination, unconscious or not. In any case, her poems are greatest and most fully expressive in the original form in which they appear in her manuscripts.