Reem is the easily the most dedicated player I've had the experience of playing with - when he says he MGEs all the time to improve let me just say he isn't kidding, my first impression of Reem was when I woke up at 2:00AM in the morning to a text in our discord simply saying "anyone down for MGE?", I knew from that moment we had a committed demo.
Although we aren't on the same team now, you can ask any demo in the main div and they will tell you the demo their team fears most is Reem, from the first stick to the two-pipe the presence he puts out is really something to behold, I strongly recommend giving this man a tryout and experiencing it for yourself. Let me just say that if main did "all-star" rosters for classes like highlander, Reem would win that for the main div hands down.
To say Reem only cares about winning isn't really accurate, and to say Reem is incapable of handling criticism doesn't fit my experience from the time I spent playing with him. My largest impression of Reem's adaptability and dedication to improve was during pre-season when we were scrimming process. We had the experience of dealing with teams that would fast bomb our demo, the first scrim went rough as some mids we weren't prepared for it (It really was our first time dealing with it!). The next day, Reem went from getting caught out to getting a free soldier pick for us telling us everything he had researched about getting fast bombed, what to do, what the team can do, and how to play around it.
The point of that long-winded story is thus: Yeah, I think Reem cares about winning and losing, but who doesn't? What you need to know is that Reem is the kind of person willing to make the change, play differently for his team if they think a playstyle is better, or is willing to do his research into how to best perform his role.
As for 7gull's current situation, all I can say is I don't know the current situation between your players, but if your method of "constructive criticism" is actively chasing your team's best I have to really question its effectiveness.
Serious Div2/Adv teams out there on a hunt for a demo, give Reem a try, you won't regret it.
-FlipFTW