As others have noted you can certainly get a lighter better quality of frame, it is just a matter of how much you care to spend. But a lighter high end MTB frame is likely have just as high if not a slightly higher BB shell. Higher end bikes are all about performance and an extra 3-6mm of BB height can mean the difference between cleaning an obstacle or not/
How long is your commute? Unless you lie in downtown Hooterville or Kabul you can, as others again mentioned sae considerable weight with different tires. If your only going a few miles on relatively smooth road a Paselea 1.75 tire will be much lighter and likely give you just as smooth a ride.
Ditching the Dynamo hub in favor a rechargeable LED light will same a few grams too.
Do you really need that giant seat bag?
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk