Besides whether the issue he's addressing is real or not (i dont agree with him), this is not the way to address the company you work for and i would completely agree with Adobe if they do fire him for this.
I wouldn't fire him but I would ask that he be a little more informed on how modern technology works before going on a rant about it. Especially when he aims his complaints at his own company. There are REASONS for some programs to load slow, it's not like everyone is competing for the slowest loading software.