Early 40's now bro. i've played heavy basses and enjoyed the heck out of the tone - i sometimes borrow my pal's P bass which weighs a ton. Heck, my new (to me) USA hamer B12L is pretty stout.
I have a bad T9 disk (bring out the violins) but even if I didn't it's all about the amount of time you play at a gig.
I liken it to meeting a drummer who brings a piece (or larger) kit to a gig. First thing I think is "you don't gig much do you?" - Virtually all the pro and working drummers i know use 4 pc kits because they're sick of lugging around one more thing. I know some cats gig a lot with 8x10 and 2x15 cabs, but if you did a poll based upon number of gigs a person plays - you'd find a very large skew towards bringing smaller gear (maybe two smaller cabs, lighter head, etc). I see the same thing with PA size - the band that plays once a month or less brings a monster, while the band that plays every week brings a more efficient system.
I said all that to kinda set the stage - If you gig a lot, you're probably going to gravitate towards lighter basses. Most gigs I do now are two LONG sets. a kilo makes a huge difference over the course of 1.5-2 hours during a set.
This isn't unique to musicians - find someone who does anything very frequently - (hobby or professionally) where they have to schlep stuff around and or hold it for a long period of time and more often than not they're using lighter more efficient stuff, and bringing only what they need.
