I'm not sure if you're looking for a real answer or not, but it's because you get super personal.
Most on here would agree that players can be criticized, and actually, most do criticize the players. But there's a huge difference between criticizing the path a safety takes to the ball and casually calling our players idiots or saying that food should be withheld from them as a punishment, both of which you have done. Saying such punitive stuff like that about Tech student athletes is really going to sour people on you.
Similarly, when a player announces he is transferring, it's fine to say "Sad that it didn't work out but we'll survive" or "Wish he had lived up to his potential here, good luck to him" or even "Not a huge loss given how bad we are anyway". But it is not the time to immediately go into details about why you think he sucked, or call him lazy, or say things like "He played with poor discipline, he played as if he never studied Film a day in his life, he was constantly caught looking at the wrong Keys, making the wrong reads, etc."
It's just not something you do to someone who played for you, especially not an unpaid student athlete.
Obviously it's a free country and we are a board with very lax rules about what you can say, but if you're wondering why you get these types of reactions, that's why. (By the way, you often get personal in discussions with other posters too, which again is why you get bad reactions focused more on attacking you rather than the substance of your posts.)