Why must the good ones get abandoned? Can the talented developers actually finish what they start please? There's too many good games now that are getting abandoned, or just milked for money, when in reality, they might as well be abandoned.
I don't know which case Mad World falls into. Perhaps none, and it will continue. But unfortunately, many, many games get abandoned here, probably the majority.
There are three main reasons, I think.
1) The game just doesn't make enough money. If a dev is spending 60 hours a month working on his game, and the game only makes $250 a month or so, that is less than minimum wage in many countries. So, unless it is a labor of love, the dev just doesn't need money, or the dev is from a country where a few hundred US dollars a month is substantial, many devs call it quits after the donations plateau at a few hundred a month. Maybe they create a new name and try another game. Perhaps they focus on another type of job.
2) The game makes too much money. After a game hits the few thousand a month mark, many devs, those without any personal integrity, start to think that why should they work their butts off and finish their game, just to have the donations immediately cease once the game is finished? They realize that they can drag out the release cycle to 6 months, 8 months, more than a year, or even forever, and still make almost as much monthly income as if they were working steadily on the game. This is the issue with the Patron model. It gives devs a strong incentive to start their games to get donors, but once they hit a solid level, it encourages devs to drag it out as long as possible (otherwise known as milking).
3) This last reason is all too common, unfortunately. Computer types, aren't always the healthiest people, either physically or mentally, or even both, so things happen in someones life that makes creating a game, very low priority. Health conditions, family problems, work problems, war in their home countries, etc. There are many reasons why a dev might stop working on their game. It isn't their main job, which they need to pay the rent and bills every month, so they have to work whether they feel like it or not. Creating games is more of a side hobby that makes a little extra money, so any problems in a devs life, and it is often the first thing to go.