Yes, always has been, from the lowly Fighting Man of 0e, to the stolid %STR/extra-attack early 1e fighter, to the crazed dual-wielding/double-specialized DPR machine of later AD&D, to the elegant, highly feat-customizable yet still disml-Tier 5 design of 3e, to the balanced, competent defender of 4e, back to the ExtraExtraExtra Attack fighter of 5e. Regardless of whether the fighter was good, bad, balanced or indifferent, it's popularity has never waned. People want to play fighters (and Rogues, Barbarians, Warlords, Archers, Swashbuckling duelist, martial artists, etc), and they have often been unhappy with the choices D&D has offered.
WotC has radically changed the Fighter with each full edition they've published. And with Essentials, which was more of a half-ed.
TBF, that's exactly what precipitated Essentials, and drove Next (5e), to re-entrench(pi) the martial/caster gap. It just wasn't one thread, it was every corner of the internet where D&D came up.