A lot of the potential issues with newbie beer quality can be narrowed down to over-utilization of one single ingredient: LME. If there is a stigma against extract brewing -- and I do think there is -- it is rightly so, and I think it often/usually comes from using LME. From the moment LME is manufactured, it is beginning to oxidize, stale, and darken. The flavors after a couple weeks on the shelf are not the same as the day it was manufactured. But freshness within a couple of weeks of manufacture until brew day is rare, if it happens at all. Several months later, the extract is quite a bit darker and has a consistently stale caramel-like flavor. Complaints from newbs along the lines of "all my beers taste the same" might today be less common than they were 20 years ago, but undoubtedly are, or in my experience should be, still happening.
Spot on about LME. My advice to new homebrewers is to start with extract but avoid LME at all costs. Always use DME. Every once in a great while I do an LME brew, to see if the situation has improved, and it always turns out to be a dumper. The same recipe with DME, and all else being equal, wins awards.
The stigma against extract brewing may be because old farts like me started out brewing with LME and made terrible beer (I don't recall if DME was available in the mid-90s). To be fair, this could very well have been because dry yeast at the time was also bad. Nonetheless, LME + age+ warm storage = bad beer. The high water content of LME = poor shelf life.
But if you ask me the biggest reason newbies tend to make bad beer, regardless of extract type, is because they do not have good temp control for the fermentation. They are just starting out in the hobby and don't necessarily have a fermentation chamber plugged into a temp controller. This is a HUGE hurdle. Sure, newbies could be advised to use kweik yeast so they don't have to worry all that much about temp control, but I'll pass on drinking an IPA that was fermented in a 78-degree closet,
especially if it was a kweik yeast. Granted, temp control is less of a concern for a 1-gal batch than a 5-gal batch because of SA:vol ratio, but it's still a concern.
The temp issue is somewhat the fault of yeast mfrs. When Wyeast says you can ferment a 1056 beer up at up to 72 degrees, for example, they don't clarify that this refers to the max temp of the fermenting wort
inside the fermenter, not the max temp of ambient air temp inside the closet. Cue the extreme attenuation and ethyl acetate and fusel alcohols.
And so newbies make marginal or bad beer and ask themselves, why would I want to keep doing this? It's a very logical question to ask. It doesn't help if they read "it's so easy to make good beer at home!" Actually no, it's not. It takes a lot of time and care and at least some specialized equipment, and if the product sucks, I don't blame newbies for not sticking with it after a few attempts. If I'm told over and over that I can make a canoe from a log using just a chainsaw, but then the canoe doesn't float or tips over, then forget it, I'll just buy a canoe.
To get good at something, you have to practice it. Millenials don't have the patience--and, to be fair, perhaps not the time--to actually learn, over time, how to do something well. And it doesn't help that the homebrewing industry misrepresents how challenging it is to make really good beer at home, beer that one would actually pay for.
To you Julia, a philosophical question: What if the hobby has grown all it is going to grow, and it is at a more or less permanent plateau? Old guys like me ascend to the hop fields in the sky, someone replaces us, and the number of homebrewers stays more or less constant. Would this be a bad thing? Why is "growth" an imperative? Is there anything wrong with staying the same size and simply "maintaining"?