Why do jumps in the second half of a program score more?

In Junior and Senior singles, the Base Value (but not the GOE) of certain jump elements in the second half of the program is multiplied by 1.1 to give credit for an even distribution of difficulty in the program:

• Short program: the last jump element performed in the second half.
• Free skating: the last three jump elements performed in the second half.

Each factored Base Value is rounded to two decimal places. The second half starts in the middle of the required time, without counting the plus or minus 10 seconds allowance. If a program is interrupted for up to three minutes, the 1.1 factor applies only to jump elements started in the second half but before the interruption.

Source: Skate Canada, Scoring of Skate Canada Competitions, https://info.skatecanada.ca/index.php/en-ca/rules-of-sport/52-marking-of-skate-canada-competitions.html