Same reason I did, and becuase my specialist specifically said to not get the Pfizer or Moderna "vaccines."
I got the J&J shot in April 2021. I will absolutely not be getting any more Covid-19 related shots/boosters/clot-shots. Anyone who's kept up on the mRNA vaccines knows they're poison and killing people world-wide.
I wouldn't get another J&J shot either, were it available. I've had Covid twice, survived both times, confident that when I get it again (as we all will eventually..) I'll survive it just fine then too.
Same exact story here, except I had no specialist guiding my choice, just that I needed to get vaccinated because of my immune system issues.