Sure the times are changing. Everyone is getting more liberal/PC. There are more colors added to ranking for and profiteering. Other arts and instructors had surfaced. So too, has other martial art fads.
Fighting fads in chronological order:
Boxing in the 40's-
There were boxing gyms all over. Fathers (parents) and priests would settle boyhood arguements by "putting on the gloves".
Judo in the late 40's to mid 50's-
Because of the lasting memory of the Pacific War, and the Japanese look more of a enemy than the Germans, things Japanese were not readily accepted. Soon, Judo started to gain its fad popularity. Judo was sheik. Just look at the old action films and old James Bond movies.
Karate in the mid 50's to early 60's-
Because of the American occupation on Okinawa, Karate was being brought back. Karate was gaining over Judo cause it seemed "new". it had more "action". And the famous "karate chop" to the back of the neck in entertainment.
Kung Fu in the late 50's to 70's-
The mtyhs and mystique of strange moves and feats were tempting. There was even a song added to the fad; "Everybody WAS Kung Fu Fighting". Credit Mr. Bruce Lee and small budget HK films-with all of the "strings attached".
Ninjutsu and PKA in the 70's to early 80's-
Wearing a "black hood" was not considered "terrorism" back then. It was "kool" to dress in black and use stealth. PKA/kickboxing was black belters whom wanted to contend. Back then it was truely KICKboxing, people were getting knocked out by the foot. Nowadays kickboxing is a exercise/cardio fad with another name stemming from calleshenics, aerobics, jazzercise, etc. Competiton kickboxing now has little Kicking, per action. Being it should be renamed to BOXINGkick
Ultimate fighting/Shootfighting/Ground arts in the 80's til
With movies such as "Kickboxer", bouts seemed harder (as cage matches were not really new). Because there are RULES, grappling seemed to dominate these bouts. These were later to be developed into electic systems termed "modernized". Although, the martial arts, since the beginning of human physical conflict, has beed modernized in accordance with its ever changing eras.
Shaolin Kung Fu/Krav Magna/CDC
Again, media, per movies and perofrmances had caused a re-curiousity of Shaolin. China went from a culture deprived/harnessed country, to re-enrichment of it past. Shaolin had market value. Get a couple of old men and wu shu practitioners, shave their heads, and presto-. Krav, was just another military martial art to show effectiveness.
This time line is per fad, or given surgence of these, in my environment or residency. Now, it should be noted, that I do not intend belittle any particular martial art, its organization, its individual instructors, or people. I like ALL martial arts. I have studied a few martial arts and have friends in many others. Generally, I see people over-hyping, or bandwagoneers, of a particular martial art. Reading posts like this vs that. This is better than that. TMA vs MMA. Given the definition of martial art, then boxing, military armed forces, or anything to do with fighting/combat could be considered as martial arts.