Mr. Beer kits got me started in the hobby and I still use it to this day after 6 years. I have wanted to get into AG brewing for years and am recently being able to throw money at the equipment, but having a small 2 gal. kit from Mr. Beer, and having some experience from brewing with some AG homebrewers has given me the knowledge that only using the Mr. Beer kit would not allow. I have amassed several tools, like hydrometers, thermometers, worth chillers, etc. all in hopes of getting to AG, and those tools, along with Mr. Beer kits and AG field trips have fueled creativity.
I wish the instructions on the Mr. Beer kits went more in depth, as some have said, as to the WHY of the processes rather than overgeneralizing everything. I had, for the sake of this conversation, researched brewing beer for a year or so before being gifted a Mr. beer kit, so I was able to understand the WHY of the steps that were being presented. I've also made some really good beer with the provided ingredients from the kits, and when I got legit brewing tools, they helped even more. I usually make a Mr. Beer kit and make sure I'm pitching at proper temps, keep the fermenter in my cool basement and shielded from sunlight, measure OG and FG... but I usually do something to the kits that I think is different. I'll add fruits and jalapenos, hell I made the American Ale kit last month and added cold brew coffee and bottle conditioned for a month. The coffee roaster I gave it to loved it.
You can make good beer with Mr. Beer kits. I think the directions should be more in depth, the ingredients should be better quality, and more equipment is necessary to deliver consistent results. I think I used Safale 05 yeast, for example, for my cherry sour, and I'm about to keg it up and carbonate it, I'll let you know how it goes. It was a Mr. Beer American Light Ale kit to start. You could use the fermenter for AG stuff too, it's great for smaller test batches. I do not like that there isn't an airlock, but that can be easily fixed if you know how to fabricate a seal and a lid for the fermenter. You have to sort of want to learn for Mr. Beer kits to be successful, and I think that anyone who gets into homebrewing will want to do that and really expand from there. Cheers!