"Early on, you could have made the case for Travis as the lead, but his character disintegrated into sort of a whiny sidekick," wrote Forbes. "It's kind of a mess."
Other reasons given for the show's slump include the lack of decent villains, no source material (The Walking Dead is based on Robert Kirkman's hit graphic novels) and viewers suffering zombie burnout.
In a review of the show's most recent episode, The Guardian said it needed to prove why it existed.
"Fear the Walking Dead has taken on the qualities of its zombie subjects: boring, poorly organised and slow. Its characters are hard to care about, its plot twists ripped from the original series and there don't seem to be any psychological insights that this show can find in the apocalypse.
A Forbes reviewer praised a high-stakes pier stunt, but said the show's "good moments still don't add up to a coherent whole".
Many reviewers have criticised storylines for splitting up the show's main characters into separate groups.
Despite the ratings slump, Fear the Walking Dead has already been renewed for a third season of 16 episodes.
Curtis recently told the Herald he had begun training for it, and shooting would begin at the end of the year.
Read more: Cliff Curtis reveals his Hollywood horror story
For those that can't get enough of zombies on TV, The Walking Dead's seventh season kicks off in late October.
In New Zealand, Fear The Walking Dead screens on Sky TV's SoHo channel.