Yes, Eharmony is a bit of a joke in many respects. Their success is due more to a massie ad campaign than any real magic in finding compatible matches.
In general, I've found the people on eharmony to be more interested in finding a life partner than dating. So far so good.
However, I've found almost no real logic in who they match me with. They bill it as magic, but it still appears to be a numbers game. If they send me x number of profiles for y months, EVENTUALLY, they'll send me someone compatible, at which point they can brag about how well their system works.
Eharmony should definitely switch to a system where they make match recommendations, but users can still search their entire database. If they're sending me so many wrong matches, I'm sure they're NOT sending me some right ones.
Other negatives, they do, (and will admit, just ask them), that they create matches between non-members, who you will not be able to communicate with. It is their philosophy that the non-members/ex-members will see the value of their service and join up.
Also, the website itself is rather poorly laid out. Good design is definitely not their forte.
That said, I HAVE met some decent people on eharmony, even had a six month relationship that unfortunately fell apart, but it was a good match otherwise.