How anyone can justify murdering a bunch of construction workers then burying a foreman alive (to which it isn't even known if he did anything in the first place) because Kendl got her feelings hurt is beyond me really. I understand that from her perspective, dressing the way she wants and such then proceeding to get called a hooker is insulting but it does not justify literally massacring people doing their day job, the same as any other characters committing acts of domestic terrorism isn't justified with or without context.
You don't actually have to murder a bunch of construction workers, though. Your instructions are to 'scare off the construction firm' and to do this you're told to destroy five portables and kill the foreman. It's completely up to the player to massacre people who are just doing their day job, if you can consider standing around all day and attempting to solicit hookers (or women they presume to be hookers) a day job, as it often is throughout the series. It's brutal on CJ's behalf to bury a foreman alive in order to claim some land, true, but let's not pretend that Niko didn't murder three union officials on a construction site so that Playboy X could 'impress' Yusef Amir, or that Tommy didn't blow up an entire building and its workforce just so Avery Carrington could build condos for rich people.
Also, I was actually unaware until now that CJ clears out the land in order to take it over himself. If I'm honest, that actually makes the mission (or at least the idea of it) a lot more appealing to me than when this was just a topic about CJ burying a guy alive. To me, he's just doing what every GTA protagonist past and present has done except for himself, which I find quite favorable. Looking at the "Deconstruction" mission it's basically just a rehash of "Demolition Man" except the motive for the mission is the protagonist's own gain, which I don't find disagreeable.