Most Bangladeshis don't care about Pakistan because people to people contact is extremely limited between Bangladeshis and Pakistanis. Bangladeshis mostly connect with Indians because we are surrounded by Indians from all sides. So its hard to ignore them.
Most Bangladeshis extremely despise the state of Pakistan due to brutal genocide in 1971 by Pakistan to Bangladeshi people but this hatred is limited to the country Pakistan , its army, Taliban and other radical elements in Pakistan, not the common Pakistanis.
Some Bangladeshis have inferiority complex over skin color and height and wish they could be as 'fair' and 'tall' as Pakistanis. Bangladeshis in general are obsessed with fair skin and tall physique as we are not 'blessed' with fair skin and tall physique naturally. There are exceptions here and there but more than 95% Bangladeshis are dark looking like South Indians and majority of Bangladeshis are short to medium. As Pakistanis comparatively far superior in looks department than Bangladeshis most people here envy you guys for your outer look.
Bangladeshis are Muslims (90%) in majority but due to Hindu culture of Bengal for thousand of years the landmass got a culture which is a blend of Hinduism and Islam. So you will see a Bangladeshi woman putting a red bindi (Hindu symbol) on forehead which will look strange to a Pakistani.
Bangladeshis don't like Pakistan as a country but has no ill feeling for common Pakistanis.