The Bug:

Non-mob entities cannot be critically attacked, except for armor stands.

Affected Entities:

Here is a list of all of the non-mob entities in the game that cannot be critically attacked. I've also provided the different types of attacks that can be performed on these entities, so you can visually see the issue.

 - Can be performed.
 - Cannot be performed.

Entity	Weak	Strong	Knockback	Critical	Notes
boat
chest_minecart
command_block_minecart
fireball
furnace_minecart
glow_squid					Strong attacks are being tracked in MC-212594 and critical attacks are being tracked in MC-212236.
hopper_minecart
minecart
shulker_bullet
spawner_minecart
tnt_minecart

Additional Information:

Item frames, glow item frames, leash knots and paintings, cannot be attacked in any of these four methods of attacking, and this is most likely because they have dedicated sounds for being destroyed.