I can totally relate to being annoyed by Preston, but personally I love the settlement building. It's not just an 'extra' or a tacked on bonus to me. It's a central part of the game. I can understand how someone would not be too fond of it, but many of us thoroughly enjoy it. The bright side is that it's optional. You can avoid it by just not building more than one, or you can limit it to just a few. You can still complete the quests to unlock the settlement, but after doing so just send the settlers to your pre-existing settlements. Building the radio beacons is part of the quests, so you can just build it and scrap it later, or turn it off in case you change your mind and want to build on it later.
Alternatively, you can elect to not join the Minutemen or simply elect to not help the other settlements when Preston asks you to.