I kinda have a soft spot for JP3 but I will admit a big reason is nostalgia and the circumstances around me seeing it. So as a kid growing up in the 90s before downloading and streaming really took off, I was mostly limited to seeing movies at home and that was limited to what we had on VHS or what aired on TV. We had JP on VHS and I remember when TLW came out we rented it (back when renting VHS was a thing) and that was a really special memory at the time. Fast forward a few years and I had gotten money for some reason - possibly birthday gift. I was thinking about buying some movies at a store to expand my collection and there in the shelf it was - JP3. I didn't even know they had made a JP3 (as I couldn't follow news at the time) so it was an instant purchase and I probably rushed home to see it, and then probably saw it another 10-15 times in the next 2 months.
While not a great movie I do appreciate parts of it. Yeah William H Macy and Tea Leoni are very annoying, the "Alan"-raptor scene is a farce but the dinosaurs still look a bit more realistic because we're not in "everything has to be CGI" yet. The bird cage part is great. The Spino is solid. There are some other scenes that have stuck with me. One of my biggest laughs across any of these 6 films is Alan Grant going "No force on earth would ever get me to that island again" followed by the 'we can write any number we want on this check' scene and him going.
Also while it's not a huge focus of the movie by any means, I always liked the small 'mystery' scenes when they talk about how the Spino wasn't on InGen's list and them speculating about what InGen really were up to. Sometimes those scenes that leave a lot to the imagination are more memorable than them trying to over explain everything.