You do know that shoving a thorny redwood up your star fish every time you log on the internet isn't mandatory, right?
Being rude or not, he's right. If you don't find a game fun, it's not the game's fault.
Blockland, being a sandbox game, always has potential to have something different than what you've already played and seen. As a building game, you're given tools to build something you can enjoy and have fun with. You, and everyone else saying blockland isn't fun, are in complete control to make something different. You have all the tools and guides to help you do so. The question isn't why the game isn't fun, it's why haven't you
tried to have fun.
And if you don't want to make a server, there's still plenty of servers to play on, you just can't judge a book by it's cover, and you have to jump in feet first. That's how most sandbox games and or online building games work.