A tier list traditionally is made as a way to list what characters have the engine on their side, effectiveness, and basically overall well being. Some characters in tiers are actually really well. While some characters on tier lists are legit broken, some lists are made based on how hard it could be to play a character.
For example, in the Brawl tier, Ganondorf is dead last. In many aspects, he is a very underpowered character. Yet there are MANY good Ganondorf players out there who can give any character a run for their money. A lot of tier lists in this sense means that characters down the list are either much harder to play with. Even in Melee, there were a lot of players out there who still played with lower tiers characters for the challenge of it and still pulled out tournament wins.
However, some characters on the top of lists can still be difficult to play. For example, just because Falco and Fox are top of Melee tier, that doesn't mean they're extremely easy to play. It's based on player experience. In my own opinion and experience, playing Falco, Fox, and Marth in Melee was easy when I was familiar with the melee engine. However, since I play Brawl Minus more than anything now, I don't have my melee mindset anymore. If I went back and played it today, I may think they all suck because I don't know much about the engine anymore. This is where people contest a tier list-You have your own experience and opinions.
If I wrote this completely off topic, I am sorry. I thought I seen someone ask about Tier lists ^.^
As for the other stuff, I am PRETTY sure Ike is not a Marth clone. I could be wrong, but I never even noticed much of a clone besides the counter. And as for the chain-grabbing and move spams, it's banned as house rules with the set we play with in MOST cases. Someone who does nothing but spam one move is typically a taboo. However, attempting combo runs can be something completely different.