I am a huge roach fanatic. But my reasons besides that are these: 1. Roaches are common just about anywhere, so they're not too obscure. 2. We need bugs in Minecraft! Yeah we have plenty of glitch bugs, but I mean like insect bugs! 3. It could be the first passive mob that spawns at night.
Their purposes in the game: 1. They could eat any food item so you no longer need to make a junk-chest for all your poisonous potatoes! 2. You could catch them and put them in a bottle so you could... eat them? I don't know. 3. Being so small they could be very useful in making command block creations!
That's it for me! I know most people will flat-out say, "Eww no! Roaches are gross!" and bypass that lovely 'vote' button, but PLEASE! This is the one feature I've wanted for every single update! So even one vote, or just acknowledgement would be appreciated! Thank you and have a wonderful day!