What do you mean shitty traditions... It's not just with sports, it's with everything with life. Look at jobs, do you know how many people work their ass off and put in effort to earn a job but are often replaced by others because the organization/company deems them as better? Plenty of older workers are replaced by younger college graduates because companies think that they can utilize them better and mold them to better suit their goals.
The players aren't the priority because the team is owned by an organization and they should be doing whatever they can to accomplish their goals, such as winning the LCS or getting to worlds or whatever. Replacing players for a better chance to succeed is just a harsh reality. The players put in work and effort to get the spot but aren't good enough for what NRG hopes to accomplish. It's not like the other players, like with other professional sports, didn't bust their ass to earn their place as an established veteran.
The players are merely tools in accomplishing the organization's goals. Team Coast made a team that advanced to the LCS, Team Coast sold the rights to the team to NRG, the players of Team Coast's contracts ended (IIRC), and were replaced by better players that hope to achieve NRG's goals in LoL (I'm assuming it is to win as much as possible).
It's a business and a harsh reality. Being a professional athlete/gamer isn't easy; being a professional anything isn't easy. The thing is that the players aren't entitled to anything because it is not their team, they just play on it.
Similarly, Regi took DoubleLift and basically kicked WildTurtle off of the team (obviously, it's not that harsh and I believe he's been helping Turtle look for other offers) but that's not an issue? Shouldn't WildTurtle be the priority since he put in so much work and effort as a member of TSM for the past 3 or so years? Also, Xpecial was kicked off of Team Liquid because they thought he was replaceable and thought they could get a better support (Smoothie), but shouldn't he get a priority for helping Team Liquid become a strong NA team and get first place in the Summer Split?