Very early in this thread someone posted that they couldn't understand why people ignore good advice and buy prefab coops anyways. I just wanted to post an answer to the "why" I personally went with a cheap prefab coop. I hope this helps explain why at least this person would buy these coops even though thread after thread bashes them.
I was well aware that the TSC coop would be insufficient in the long term, especially if I added any more birds. I knew it wouldn't hold up for years and was flimsy. I also knew it was not generous in size. So it was an educated choice and not flippant.
Before my chicks arrived in the mail, I had never held a chicken or chick before. I had researched extensively what was involved in caring for chickens, but there is a world of a difference between reading in a book and slogging out in the rain to take care of chickens. So I figured there was a decent chance that I wouldn't make it through the winter before deciding I didn't want to keep them. Also, I was the only one in my household supportive of getting chickens, and if I didn't have time for them, I would have to get rid of them. (Just to reassure everyone, I had a rooster plan and a get-out-of-chickens plan)
In addition, I was bombarded with negative feedback that said every chicken has an extreme death probability at every point. Order twice as many chicks because a lot will die. But just wait, as they grow up, more will die. Just as you get eggs, predators will kill them all, etc. So I had no idea how many chickens I would actually have in 6 months! I figured I was very likely to have 2 chickens and thus the tiny coop would be fine.
The final factor was that I have little carpentry skills and it would take a LOT of time to build anything. I see a lot of comments like "just whip out a huge coop in a few days"! I wish I had that much ability and time in a day, but that doesn't apply in my case. It took me a bunch of weekends just to get a prefab coop set up LOL! I can allocate about 3-4 hours a week to building anything and thus it is a year project to build a "real" coop.
I figured I would know by the end of a winter if I was stuck on chickens and then I would start building a "real" coop. The prefab ones make great quarantine and brooding cages, so it isn't a waste of money and can be reused.