It depends on the type of riding being done.
If all 230 pounds of me was complaining about needing a full CF rig with low-count deep wheels, wing bars, and and aero seat mast for a 25 mile recreational weekend ride around the park, heck yeah I'd expect people to laugh. It's unnecessary and won't do any good.
When all 230 pounds of me complains about wanting to lighten up the load on my rando bike by a pound and a half it doesn't sound significant, until you consider the math. Over the course of a hilly 100km segment it may only save me 2 minutes...
Link 4 of those segments together and it becomes 8 minutes, and I might need that time for a flat repair or a navigation correction in the middle of the night on a 400k brevet. On a 600k, it piles up to be enough time for a quick nap.
It's like looking at generator hub resistance, and initially you might look and say "Pfft. What's 1.5% in the overall scheme of things?"
If you're riding serious, timed long distance events like randonneurs do, it can be significant. Over the course of a 1200km event with a 90 hour time limit, that 1.5% effort totals up to 80 minutes, which could be the difference between making a control or DNFing.
__________________
"I feel like my world was classier before I found cyclocross."
- Mandi M.