This is definitely a major issue with aircraft that are designed differently (twin-boom for example), made worse when the aircraft was modeled with one system in mind before being forced to another.
For example, the P-38 realistically has a very strong twin-tail, so very high amounts of damage must be done to it in order to destroy the tail. This is correctly modeled in-game, I have experienced this when flying so low that I momentarily tap the tail to the ground, at speed.
I would consider this boom as “no longer having structural support”.
However, because of the blanket effect of Severe Damage instead of the careful thoughts of “what lets this plane fly?”, we get instances where mild damage occurs and the pilot continues to fly, only to have a death counted; and other instances where any sane pilot IRL would bail and no death is counted - the player merely pays a small repair cost at the hangar.
In reality, the real issue of Severe Damage is forced ejection at the end of the match. If I have ruined a plane to the point of writing off at the end of the match, bill me a full repair cost as befitting a “written off” plane! Don’t kick me out of it, as though my pilot made the illogical move to eject from a plane still functional. Trust me, flying as far home as the broken plane will take you is significantly faster (at least, initially) than having to walk the entire way to base on foot.
What I think Gaijin misunderstands is that players do not like game mechanics that “intervene”. I stopped playing Arcade not because it wasn’t fun or that the grind was slower, but because I was forced to leave the plane in instances where I would have liked to continue fighting or was capable of returning home.
I was still flying - let me fly!
I have also commented on the bug-report website @_Poul and @Loofah have as well - Community Bug Reporting System
My sentiment is echoed here by forum users discussing in the original feedback/suggestions: [Development] Testing out the Severe Damage mechanic - #114 by _WiKi