[Amps] SB-221 Why is the the variable load capacitor only crimped to the HV circuit?

[Jeff King]

Heres a question for the Heathkit experts or former designers.
The Heath manual instructs that the connection of the variable load
capacitor to the HV circuit should only be crimped, as a mechanical wire to
wire connection. 
Why was this not soldered? Surely that would make a more reliable electrical
path for such an important component?

Jeff ZL4AI