Because I find them really annoying. I used to think they were cool because they gave hints on how to survive next time and what killed you exactly.
But honestly I learn better by watching my team perform the mechanics if I am dead, but that re cap screen is really obnoxious and just blocks my views of the fight.
Ideally i'd rather be alive and fighting still while learning it, but in a non perfect world that is not always possible and I die because I did something wrong. I want to be able to see what my team mates who are not dying are doing!