1* Leaders? Why?

With frustrating regularity, I see allies setting 1* or 2* (level 1) units as their leader, which makes them pretty much useless to all of their allies. Can anyone explain why people do this? Often it's during events, when we need strong allies the most - I just don't get it.

Is it a rank thing? They've attained a high rank in the event, and figure setting a weak leader will prevent their allies from potentially doing well enough to pass them?

Or is it just a douche move, for no real reason?

Honestly, if there's a good reason to do this, I'd love to understand.

There are 3 reasons i see 1* / 2* leaders

1. they quit
2. they are auctioning monsters
3. they are using Claudio

I've had an ally do that every time.
Also for events like the current they would NEVER give anyone an assist, but would always ask for them.
Quickest, and only solution I found(and why I used past tense in the 1st line) was to remove them, and replace them with one that isn't a prick.

whats claudio?

Claudio is a 2* who's skill is Attack Boost (female) 2. if you have the global skills Seal of archangels at 10 and Battle Seasoned, it becomes 3.3 (3* 110%). that gets added to all female allies in the battle.

Great for Mina's Trials events