I'm not sure exactly when badly-executed cliffhangers became such a pet peeve for me. Perhaps it was with Gundam SEED's ridiculously built-up event of Kira getting shot at with a gazillion missiles at the end of one episode only to shoot them all down in the space of the opening thirty seconds of the next. Alternatively, maybe I just am lashing out at repressed memories of those old Adam West Batman episodes.
My point is really this: cliffhangers, especially in amateur works, are often very, very stupid. And they're stupid specifically because of the reason I mentioned above. They oftentimes will introduce some big and terrifying thing that represents impending doom for the protagonists, and then it gets conveniently dealt with in the opening moments of the next episode.
There's a time and a place for this. The time in question being the early 20th century and the place being old serials that didn't have a large budget and didn't have much time for each installment. Like the Tintin comics of old, serials had to make each episode end in an exciting way in order for people to keep coming back so they could keep getting money. And even then a lot of times the various perils and their solutions were badly thought-up. Nowadays, they're still used from time to time, but if they are in a bad way (especially in a serious work) people are going to cry foul.
Cliffhangers should not be a cheap way to end an installment in a story arc. If they're there, the perils they provide should be serious enough that they're not solved within the opening moments of the next episode. In the event that they *are* they should provide serious repercussions to the rest of the story. If someone gets shot, don't just magically make it so it just winged them and they're perfectly fine. If someone seemingly gets killed, don't have them get resuscitated in five seconds and be back up on their feet five seconds after that.
In the event the story needs that event, there's absolutely no reason you couldn't put the resolution at the end of the previous episode as well if the problem was that easy to solve.
Long story short, a bad cliffhanger makes people come back to see the resolution. A good cliffhanger makes people come back to see the aftermath of the event.
For example, let's use a hypothetical example with Batman. A bad cliffhanger with him would be featuring him getting shot in the chest and then devoting maybe the smallest possible part of the next episode to showing he really was okay or, if he was hurt, magical bandages will make his injury no longer hold him back. A good cliffhanger would still save him in some way or another, but the repercussions of him being shot would continue to be prominent through the rest of the next episode.
In other words: when writers write themselves in a corner and can only get out by Deus Ex Machina. Hate those too. Reason why I REALLY didn't like Fairy Dust.