Can you be specific regarding why you had never or would never consider using CI?
Not really, it was a long time ago and I have never given it a second look.
The first thing I remember though was simply it's coding standards, its ugly, I remember that. I also remember it going against a lot of the design principles I had learnt through working with Python. God like "core" objects, static methods scattered throughout, zero testing and an Active Record based ORM. Better frameworks already existed for PHP at the time, Codeignitor was not doing anything ground breaking or improving on this.
How and why was that decision made?
What kind of developer uses CI, and how is that different than you?
People with little experience with OOP and good design principles
Also, in what way do you think CI has done harm to the php landscape?
Because it has since taught a lot of its users bad design. You can still see some of these tendencies in other popular frameworks. A lot of CI people have been drawn to Laravel for instance because they see the Facades as providing them with the same Static interface they've grown to love (all be it a lot better implemented under the hood).
I'm looking for specific facts regarding CI's deficiencies, problems, etc.
I'm sure you can find plenty of articles on the subject.
Could it be that it's just popular to hate CI?
I've never liked CI. Those that use it may be in a bit of a bubble but it's always been that way from my view.
You mentioned that CI may fill a need for some developers. Can you elaborate?
I understand that people who can simply ignore the bad design or people who are blissfully unaware of it "can get shit done". Much like how a lot of people can "get shit done" with platforms such as Wordpress. Truth be known, there is a lot of bad PHP code around that enables people to "get shit done", still, this doesn't change the fact that it is crap code.