Ah, yes, Turf War in Splatoon 2. I believe I've written half a novel about how much it has changed already, but to recap the most important points, yeeeep, Splatoon 2 puts emphasis on "War" in Turf War and I ain't kidding you there. Now what you (hopefully) mean are the hyperaggressive Players who are only out for Splats and ignore the objective (i.e., inking ground). Sadly, there is no way to avoid players like that altogether, but there's ways to more or less deal with them should you find these notorious wardogs in your lobby:
Case 1: The "hyperaggressive players are on my team, halp?":
While annoying to see that, if they're successful at picking off enemies, good for you! Focus on keeping area control inking as much ground as possible and covering walls on the enemy side to slow down their pushes. In this scenario, you don't have to focus on getting many splats by yourself. This is the best case scenario for your current playstyle, I think.
Case 2: The "hyperaggressive players are whooping my rear all the time :c"
Now that's where things get really interesting... depending on how aggressive they are, you won't be able to just ink away and hope for the best. Salty players or not, splatting people to keep control over the map is crucial to each game mode. While these fellas may take the splatting a tad too seriously, you've got two options to deal with them: either, trying to avoid them and hope your team will sort things out for ya, or see if you can spook them away using your subs, or, well, try to face them and turn the tide.
Case 3: The "There's hyperaggressive players on both teams, I can't see anything through all the bombs and corpses e_e"
Uh, open up that map every now and then and see where the beef is at and see if you can sneak past the heat of the battle, or even abuse that situation and pick off busy enemies, then go back to turfing. And, good luck. Bombs raining left and right can be quite a sight to behold, lol.
That's super simplified and overgeneralizing, so if you want more specific tips, what weapon are you playing? Some weapons are better at dealing with these kinds of players than others - and ultimately, even if you can pull off the avoidance game in some lobbies, you'll have to deal with them eventually, otherwise you won't learn how to counter them effectively. I know it's very disheartening to get destroyed by these kinds of players all the time (had this brutal awakening when I thought I could still use chargers in S2 like I used in S1 when I bought the game, lol), so I'm sorry to hear that you're being this unlucky. The matchmaker is all kinds of borked right now and puts newbies and competitive folks (read: single digit levels and level 50) in the same lobby all the time. If you want to gamble a bit, try to switch lobbies after each unfortunate match until you land in a more relaxed lobby and stay there. Ever since I started "lobby-hopping", the odds of finding more pleasant people to deal with have rised unexpectedly.