you should've taken it as a comment to your question to someone else.
the change is necessary because this current form of writing Bangla was a Hindu practise. and whether it was intentionally imposed on Muslims is not as important as the fact it did replace Muslim writing practise in Farsi and Urdu. historically, when Muslims would want to write something in their *own* language, they would do so using Farsi, Urdu and Arabic (the latter mostly as a spiritual language). if they wanted to write in Bengali, they would have to learn and write in the Bengali-of-Hindus. because the Bengali-of-Muslims (Nastaliq Bangla) was not very mature or not fully standardized, as far as i have learned. therefore the predominant written languages of Bengal Muslims were Farsi and Urdu, rather than Nastaliq-Bangla. however, some of these same Muslims would use the Musalman Bangla
only for speaking and it was characterized like this:
a jargon which a Hindu will probably not understand. for only the pronouns and verbs are Bengali. and the rest Urdu. Persian. and Arabic ... This is the language to which Moulavi Abdul Karim Saheb characterises as "a kind of Bengali' which the "agriculturalists speak."
Musalmani Bangla and its transformation | Page 10
. the fact that the written languages associated with Bengal Muslims were Farsi, Urdu and Arabic only (and not Nastaliq Bangla as well) may be because of the high illiteracy of people who could potentially patronize the development of a Nastaliq Bangla. so the way Muslims established some Indo-Aryan languages in Nastaliq/Shahmukhi was incomplete in Muslim Bengal. the way i see it, Nastaliq Bangla should be promoted more to fill in the incomplete heritage of Bengali language overall, and it will only enrich the Bengali language and make us acknowledge its rich history.
only people who are intolerant of subcontinental Muslim heritage co-existing side by side with Indic or Vedic heritage in the subcontinent would blindly detest this