As many others have said already, it is not being "unable" to commit to a schedule that keeps me from raiding higher than flex.
It is being "unwilling" to commit to a schedule. To plan my playtime on what others decide.
I want to be able to do whatever I feel like (within the options I have) at any given moment.
If I want to drop off the face of Azeroth for a month, I want to be able to do that without having to worry about what it looks like when I come back.
I play exclusively for my own fun and enjoyment, and my friends/guildies that I occasionally play with, are the same.
I want to be able to stop farming x boss once I get y loot I wanted from him. To not bother farming consumables and leaving my raiding by the wayside if I feel a bit drained from work one particular week, without my next week then being harmed by it.
I want to play whichever of my army of chars I feel like any given day, without having to worry that "I need to tank the raid tonight" or "tomorrow's raid needs a healer".
I had enough of the responsability of a raider when I was raiding in BC and Wrath. I do not miss it one tiny little bit.
It was tons of fun to put ourselves to the test week after week against the hardest stuff the game had to offer, and be rewarded with prestige and powerful characters when we secured yet another server first, but as the game changed, so did I, and I do not enjoy that kind of stuff anymore.
So thank god it is no longer the only way to raid! LFR and flex came at a perfect time and dealt with my changing needs effectively.
As it is now, there is absolutely nothing for me in normal/heroic that I care about, or cannot get elsewhere.
Exactly the way I want it. I raided without really wanting to, for enough years already.