Well, it's kind of expected that if you have teammates that either feel like they are carrying the rest of their team, or that disagree with teammates choice of weapons/strategies or what have you, they generally feel like they will get better results if they have teammates that they feel are either superior to their former ones or work better in their play style. It's unfortunate that depending on how it shakes down, you can end up with teams stacking talent beyond just a 4 person team plus subs, and then you have a situation where there could be more overall competition among more teams, but a decent amount of talent that could be competing is tied up in a larger group. Eventually jostling like this can basically end up with teams completely dissolving, once one person or one starting member jumps ship, others either follow or the gap left by that player cannot be filled by another player easily, as generally people in this game specialize. There are a few teams out there that genuinely care about doing what they want to do, and winning that way, our team (CyberBullies) generally plays weird compositions that aren't necessarily standard due to our players, and we also rotate rosters almost every match, as such, it has definitely hurt our consistency(See: Calcup 3 vs our exhibition matches for Leagues). We don't really mind because we are pretty happy with our teammates and have been playing together a very long time, despite having to change names essentially...4 times, at least for me(SS-D, SS-C, Determ, CB).
Other teams that have that singular focus of "Must win tournaments" and other players that have that same goal will basically do whatever they feel necessary to get those results. Therefore, teams will aggregate players that desperately want to win and will possibly have good results, until certain players are forced to be benched or lose their spot on the roster, then they jump ship or internal drama dissolves them. I have a lot of respect for some of the teams that have persisted and haven't necessarily won a tournament,(DEG, oL, SND, etc.) and they have clearly started to get solid finishes lately. Eventually we will either see the top teams constantly cycling, and subsequently dissolving and reforming into new teams, but as long as they have top players they will get top results. That isn't going to stop until maps, modes or weapons come out that depend more on teamwork than individual skill. Right now, or rather for the foreseeable future, it will remain this way, as even just a double kill can swing an objective quite quickly. Splatoon's ranked modes as they are are mostly decided by 30 second instances of one team having a powerplay, or a team timing supers once. If we were playing something more similar to CTF with multiple captures, or any game mode that didn't have incremental scoring, this wouldn't be the case.
This isn't really an instance of teams playing the wrong Meta, it's that the Meta they are playing is the best chance for victory right now.