Asking players to consider all ramifications of their actions, and asking the developers to consider all ramifications of their inaction, are not mutually exclusive things.
Power is an easily manipulated, useless number.
Posting the best defensive line-up one can, and getting defensive wins that way is something to be proud of. It's how the game is intended to be played. It's not reasonable to suggest ppl stop playing/competing,
A candy-coated poison-pill is...something else. Trick-or-treat has an immediate effect in FP/Coli, and the recipient can learn from their mistake. Choose their attacks more carefully.
In keeping with the OP, it should be known that a poison-pill can also trickle thru the system and strike again in expo against person(s) who have little control over the opponent the system assigns to them. There is no "mistake" to learn from if stage 1.1 is insurmountable. (solo Bro is a classic)
I'll add, that lines in expo do carry the user name of the person who created it. So one's reputation in FP may travel beyond in unpredictable ways.
Disregard for..."less advanced"...players (by developers and/or fellow players) contributes directly to player retention problems.
Mass exodus has a snowball effect. Rapid decrease in population affects things like contests and GW. Even those at the "top" feel it when population collapse hits extreme conditions.
IMO every opportunity to curb population problems need to be taken seriously. To date I've personally been very frustrated numerous times that this is not the case.
People are free to act however they choose (within allowed parameters of the game). Some make an informed decision to act against the grain. So be it. Some may follow suit w/o actually thinking about it.
Anyone who intends to be a !@#$ can prolly still find a way if they want. A solo red toon is no different than one red toon w 4 white/green/blue/purp allies. But requiring expo lines to be 5 heroes would at least remove all but the most deliberate sabotage.
In my experience it is easier to change the course of thousands of players than it is to change the course of [an_unspecified_small_number] of developers. In fact most times I've witness developers take an unexpected change in course was because thousands of players took action.
I saved the best for last:
An informative plea to consider things (some ppl might not be aware of) is a very reasonable request IMO. That's a "rule of thumb" beyond this one topic thread.