My theory, probably completely unfounded, is that newcomers have a 'romantic' idea of black and white film photography mostly informed by the hyper-dramatic images of some old school street photographers. Think old Magnum war photography, poorly lit rooms, chalky highlights, overly dodged or burned details. Think also that Japanese photographer whose name now escapes me who absolutely cooked his negatives and/or prints to get those black/whites images with nothing in between.
The above is considered cool, both the images, and the mannerism around them. The photo-reporter doing gritty, dramatic 'realism', depicted several times in the movies too. Think Dennis Hopper with 10 Nikon F and 2 Leicas hanging from his neck, or the bespectacled war photographer in Full Metal Jacket.
I suspect many newcomers hold some of the above and more as examples and role models to aspire to, but often ignore that the results these people had were due to full control of the entire exposure-developing-printing/scanning chain (often also aided by an experienced master printer producing the final results).
So many people are after the above, but their only option, once they get started, is to drop their rolls at the local 'Whisky Bro Bearded Film Lab' who will only seldom return the negatives to them, and will instead send an email back with a dropbox folder of quickly made Noritsu scans which will look nothing like the images of the Japanese photographer. Add to this that very few people in this age group own Photoshop or Lightroom or perhaps even a laptop or a desktop computer, and you'll see how the 'this film is FLAT!' rubbish might have come about on instagram and reddit.
The above - again, entirely unfounded - would also explain a little why young photographers are so obsessed with 'pushing' film. This concept of 'pushing' is used on social media almost as if 'pushing' were a pro, arcane technique which will unleash the true powers of film - almost like 'overclocking' a computer's CPU. Take a walk on reddit or instagram and you'll soon find out that 'pushing HP5+ to 1600' is considered the default mode of use. People who use HP5+ at box speed are looked at with suspicion. People who pull HP5+ to 200 in high contrast settings are crucified and blessed with holy water to rid them of the disease. What push does of course, by ways of reduced exposure and increased development time, is getting them close to those 'deep blacks' with little or no intervention on their side, and the deep blacks will pop out immediately on their phone screens once they'll open those dropbox folders. These high contrast images are eye catchers when you doom-scroll on instagram too, and will perhaps attract more feedback than low-contrast images if one's attention span is low. Black and white images on social media have to compete with colour images. I wonder if to make it, they must hit people immediately with drama and strong contrasts.
Just a few scattered thoughts, please carry on. Nice video from the Naked Photographer.