'Cause I'm lazy. Every day, I use studio monitors, 2 different sets of headphones, and 2 different IEMs across multiple sources. It is just too much work to improve sound profiles I already like as they are. If I want something different, I just swap my gear, no need to mess with multiple profiles, and I never buy something I may need to fix to fit my tastes. Besides, I don't believe any target is objectively perfect or universally fitting, I WANT my gear to sound noticeably distinct when I swap them.