LGBTQIAPK actually stands for lesbian, gay, bisexual, transgender, queer, intersex, asexual (agender is also sometimes included), polyamorous / pansexual and kinky.
Many do not want "labels" or to be attached to a particular stigma from swingers to kinksters but it helps the rest of our communities understand a little more about you if we can attach something like "I am pansexual" says a lot to the party wishing to role play with you versus "I am hetrosexual"
The definition of any orientation is flexible and while "tradition" has set us up to acknowledge the two sexes, modern day people are shifting the gears to educate that is not the case, we can also start acknowledging that we don't have to therefore only be attracted to one sex either!
Some in the LBGTQ+ movement do not appreciate having the K added as they already feel that they are seen more "about their sex" than who they are but others appreciate the openness and acceptance of literally realizing they can live their life their chosen way!