Why do scopes weigh so much?

Because in order to make them light they would have to sacrifice durability. So it's a trade off.

Sure they could put lens in a cigar tube and it would be really light weight. But would you buy it??

Manufacturer do NOT add unnecessary wieght just for poops and giggles.

They could make a scope tube out of carbon fiber and that would be light but would you be willing to pay the price?????

 
Yes C_M_Shooter,
​I am certainly not a nomad, but after an hour of walking about in the wilderness, a heavier big bore gun, with a "feature rich and heavy scope", gets to be a drag.
Case in point....
1523080635_16628788525ac85dbb8c1154.47915838_Bulldog with level left side.jpg