It's June now though
As someone else who ran a raid or two and often helped select the raiders I'll say that proper rotation may seem fair to some but it's not. say someone attends a raid on Wednesday but they don;t get to the boss they want to kill, is it really fair for them to be left out of the next raid in the same instance? If they are then next time round they'll just say no to attending the first part of the raid and if enough people do that then there will be no raid at all.
It's also about balancing the raid with experience, whilst you don't want to just take the same people constantly the last thing you want to do is take a raid you know will just be a wipefest and it's pretty easy to spot which raids will be that. If a raid wipes constantly on bosses you know you can kill people lose their temper and it can set raiding back rather than help people learn so if you don't get picked for a certain raid it honestly isn't personal.
And although you probably have no clue who I am, as I have no idea who you are, you should know that I'm pretty honest and if I suspected for a moment it was personal I'd say it as I'm sure many others in the guild would. Just be patient and the time will come when you're sick of the sight of Kara.