1. If I encounter a ridiculously overpowered base hanging very low, I'll burn the whole 4 minutes sometimes. If they're sandbagging for easy wins, they're definitely wasting my time, so I think wasting their time is fair game.
2. I've learned the hard way that quitting early can lead to unnecessary losses. You never know what is happening on defence & you can benefit from disconnections or poor attacks at any time.
1. I've never pushed a high level BH very low, but on low level BH accounts I see them sometimes, not often, and wonder why anyone would bother.
2. I routinely quit an attack if I have just a bomber who may or may not eventually get one or two more buildings. Usually they don't.
OP Defense: Any defense the poster doesn’t like or know how to work around, nullifies their attack or denies them their rightful three star.
Obviously I don't know how SC coded the game, but as a developer, I can take a pretty good guess.
When you start to develop a piece of software, you design a foundation. Part of that design process involves an attempt to predict all the possible future features you might want to eventually include and make sure your design will make it easy to eventually add those. The drawback is this can make the design extremely complex, so some concessions need to be made. Developers also have time schedules to meet (you have to start selling your software at some point) so you can't spend an eternity coding a super flexible and super complex foundation.
A common analogy is building a house. Right now you only have time to build the first floor. Do you want a second floor eventually? If so, then you need to build a strong foundation and the first floor in such a way that a second floor is easy to add later (and can be physically supported by the first floor without having to rebuild the first floor later).
With the Builder Base, I think it would be a very obvious choice for developers to allow only one attack to happen at a time. Allowing multiple attacks to happen simultaneously is essentially an exponential increase in complexity. My guess is that they hardcoded it for 1 attack at a time. Adding OPs idea to quit one battle early to start another would require a rewrite of the code's foundation -> not gonna happen.
Continuing my analogy above, OP's request is like wanting to add a basement to your house. It would require destroying the foundation and somehow inserting a basement without disturbing the house and everyone inside. Not worth it.