I have a soft spot for stuff to do with the blu team because i find the color scheme more fun to draw... it just pleases my eye, not that I hate the color red I just really love the contrast the blu palettes provide
I also kinda love that there are no canon blu mercs so its kind of just become a fandom thing to draw the blu mercs with noticable personality (and appearance) differences and people come up with such creative lore (e.e cloning and the philosophical and ethical implications of that, as well as the psychological impact it would have) and ive come up with ideas of my own. its just so much fun i love it
an example would be dailyheavymedic's blu mercs, and i love that due to the personality changes the artist can depict an entirely different dynamic
i really love that the consensus seems to be the blu mercs are more serious, composed, put-together, (at least thats how it seems from the outside) and less dumb. Blu soldier is usually a bit smarter. Blu scout is typically more serious. Blu medic is less malicious than red medic (slash inspired by emesis peak- i mean emesis blu). Its a great way to see different distinct dynamics and explore personality traits which are overshadowed in the red mercs. You get the best of both worlds really :D
aaand of course I prefer blu gameplay in-game (at least, in modes where it matters more). e.e i find attacking on payload to be far more rewarding than defending and will always prefer blu, i wish there was a way to lock yourself down to attack/defense, (im p sure there was) players might be a lot happier that way, but thats another discussion