My daypack weight is around 20 lbs normally, +/- 5 lbs depending on the length of the hike. I did trim it a few pounds, but I didn't really try very hard. I justify the extra weight with different excuses, I'm packing the extra items for other people, I'm training myself to get into shape, this is a difficult hike and I might be forced to spend the night out, etc. The real reason is I just have all this stuff I want to carry. As long as you're comfortable carrying it, then it doesn't matter how much it weighs. If you're suffering under the weight, you either need to pack lighter or get in better shape. I went hiking with a guy who was carrying a 50 lb pack (this was a one day hike), but he was able to keep up wihtout any trouble so there's nothing wrong with that.

I haven't actually weighed any of my stuff, but I would estimate the breakdown to be:

Pack = 4 lbs (I need a lighter daypack)
Water+filter = anywhere from 2-8 lbs
Extra clothes = 3 lbs

the rest is just random items like food, flashlight, camera, rope, etc. I could probably cut the weight in half if I really needed to, but then I wouldn't feel comfortable. If there was an emergency and I needed to lighten the load, I can always lose some of the items, but you can't add anything once you're out there.

I just saw your list, and if you're looking to cut weight, start by eliminating the redundant items.

Mora, pocketknife, and leatherman - I also used to carry a similar amount of blades, but realized I rarely ever used one. So know it's just a fixed blad knife and multitool, still overkill, but i really like my swisstool.

50ft of rope and 100 ft of paracord - You could probably pick on or the other, depending on which one you think you'd use more. I carry 25 ft of 6mm cordage and 40 ft cord, but the rope is used more in my case, usually if I need to tie off a hand line or something.

Matches, lighter, and firesteel and firepouch - two out of three is good enough. How often do you need to start fires in 90 degree heat?

Gatorade? - if you really like it, keep it, but how often do you use it?

Waterfilter and micropur - I only carry a filter if I am pretty sure I'm going to need it.

Gaiters - I have a set that I've never used. Unless you have problems with stuff getting in your shoes (like sand, snow, brush), I would leave them at home.

Hammock - on a day hike?

Again, if you feel like you need all this stuff, then keep it. But if I were to eliminate items, those would be first on my list.