I do know there are some inconsistencies with the character, and it is partly the writer's fault, but they don't just do it with Keller. They all have the tendency to use the characters to suit the plot, rather than let the characters guide the plot.
This is true, but it's more pronounced with Keller because she has less solid character features to latch onto. From the beginning, most of the chars had particularly strong traits that were established at their introduction and hold true, even when they experience severe fits of screenwriter schizophrenia - Rodney is always brilliant and arrogant and needs to be smarter than everyone; John will go to any lengths to save a teammate; Teyla is a Pegasus native who loves her people; Ronon hates and wants to kill Wraith. So they're broadly recognizable from episode to episode, if inconsistent. Keller doesn't have a dominant trait - she's a doctor, but that doesn't inform everything she does; she's smart but not brilliant; she's uneasy off-world but that's not always relevant and inconsistent besides. It makes her hard to grab onto - for the writers as well as the audience. So the writers all invent their own characterization, and the writers who are decent at characterization (Gero, Binder) can make her appealing (if different), while in the hands of a writer who can't handle characterization (Mullie in "The Seed") she ends up having no character at all; anyone could be in her role.
no subject
This is true, but it's more pronounced with Keller because she has less solid character features to latch onto. From the beginning, most of the chars had particularly strong traits that were established at their introduction and hold true, even when they experience severe fits of screenwriter schizophrenia - Rodney is always brilliant and arrogant and needs to be smarter than everyone; John will go to any lengths to save a teammate; Teyla is a Pegasus native who loves her people; Ronon hates and wants to kill Wraith. So they're broadly recognizable from episode to episode, if inconsistent. Keller doesn't have a dominant trait - she's a doctor, but that doesn't inform everything she does; she's smart but not brilliant; she's uneasy off-world but that's not always relevant and inconsistent besides. It makes her hard to grab onto - for the writers as well as the audience. So the writers all invent their own characterization, and the writers who are decent at characterization (Gero, Binder) can make her appealing (if different), while in the hands of a writer who can't handle characterization (Mullie in "The Seed") she ends up having no character at all; anyone could be in her role.
...Ummm I am shutting up now. Really!