I think the primary design flaw is that they're built by the cheapest race-to-the-bottom manufacturer that cuts corners whenever possible. Advice like "make sure to only buy a quality one" may be useless if all of the quality manufacturers exited the business decades ago, unable to compete with the cheap flammable garbage that people were actually buying. Note how many formerly reputable brand names are on this list. The companies are hollow shells of their former selves, all buying the same cut rate hardware from some no-name overseas manufacturer and slapping their plastic over it.
There are some reliable manufactures, but the cost is significantly different. I had someone come out and give me a quote for an AprilAire dehumidifier system. The dehumidifier was $2,000, plus $1,000 installation. But they also needed an electrician to expand our circuit breaker.
I ended up going to Home Depot and buying a well-reviewed GE dehumidifier with a pump. Luckily it's not on this list. I'd rather have the AprilAire system, but $5,000 vs $400 was too much of a difference. I could replace the cheap one every a year for over a decade for the same price.
