I think what a lot of people are missing is that the party's "martial" can be played as a Druid, Cleric, Oracle, Magus... really, the only class that gets zero spells and is as effective with a big stick as the casters is the Barbarian. Mainly because the Barbarian gets great utility abilities that the other non-spellcasters just don't have (barb smash puny maze).
Slayers are quite effective.
Fighters could use some improvements. They should be the ultimate with the big stick, and aren't as good as they ought to be. They needed an Unchained variant to improve them-- not as much as rogues did, but still...they aren't as good at combat as a completely non-magical class should be.
My view is not that it's all completely equal, but just that people overstate the disparity.