We should worry about them because of their wages while contributing nothing, it's a past mistake the club should rectify to move on and because if we let them go, you can be sure the club will bring some players in. Fresh legs, fresh minds. Even squad players, that matters a lot. What message do you send to the new players when they see those players barely playing and enjoying a good salary regardless?
As for Bruno, the club extended his contract around at the same time ETH rumors started to spread. With Ralf here I doubt they would have done it if he was one of the players that need to kicked out, surely they would have consulted Ralf and if there's any doubt about Bruno, they could have just delayed it. I fail to understand how a very productive player could be problematic under a manager that's worth his mettle. Unless if he starts having off the pitch issues, I don't think ETH would consider him redundant/problematic enough to be sold. At the very basic, Bruno has always pressed when asked even though it looked pointless. With a better system, with the same workrate and his teammates helping it should bear a fruit. Hence why I'm doubting players like Ronaldo or other sleepwalking type of players because they certainly aren't used to pressing but not Bruno.
On top of that, who's to say that ETH has never had a player with limitations before? one example is Tadic. If you look at his numbers, he looks productive. Even at 33. He's certainly not as mad as Bruno when it comes into hard work. Far from it. Do you think ETH fancies a 33 y.o Tadic (whose productivity should be the main reason why he plays) but doesn't fancy Bruno because he keeps playing those risky passes that ends up to the opponent? he can just tell him what to do, what not to do, he's the boss. It makes no sense.