This 'unintended flaw'/'loophole' is actually specifically written into the F1 Sporting Regulations.
Under VSC the ONLY permissible reason to enter the pits is to change tyres:
"40.4 When initiated during a race, no car may enter the pits whilst the VSC procedure is in use unless it is for the purpose of changing tyres."
Although meant to nominally neutralise racing during a double waved yellow incident, 3 of 4 permissible overtaking opportunities involve the pit lane:
"40.6 With the exception of the cases listed under a) to d) below, no driver may overtake another car on the track whilst the VSC procedure is in use.
The exceptions are :
a) When entering the pits a driver may pass another car remaining on the track after he has reached the first safety car line.
b) When leaving the pits a driver may overtake, or be overtaken by, another car on the track before he reaches the second safety car line.
c) Whilst in the pit entry, pit lane or pit exit a driver may overtake another car which is also in one of these three areas.
d) If any car slows with an obvious problem."
https://www.fia.com/regulation/category/110