There are three kinds of lies: Lies, damned lies, and statistics.
The idea that there is "nothing special" about the La7/Spit16 is one of the second type and whoever said it ought to be ashamed of themselves. 

Okay, here is some of the 3rd type:
Late War Tour 108 Statistics for BnZs
     Kills    Deaths
   Kills In    Kills Of  KilledBy Died In
A-20G    0    1    0    0
A6M5b    0    5    0    0
B-24J    0    5    1    0
B-26B    0    1    1    0
B5N2    0    1    0    0
Bf 109F-4    0    2    0    0
Bf 109G-14    0    1    2    0
Bf 109G-2    0    1    0    0
Bf 110G-2    0    1    0    0
C-47A    0    1    0    0
C.205    0    1    0    0
F4U-1A    0    1    1    0
F4U-1D    0    2    0    0
F6F-5    0    1    0    0
Fw 190A-5    9    2    0    6
Fw 190A-8    0    4    1    0
Fw 190D-9    4    1    4    1
Hurricane Mk IIC    0    2    2    1
Il-2    0    1    0    0
Ki-61    0    1    0    0
Ki-84-Ia    0    2    0    0
La-5FN    0    1    0    0
La-7          20    3    2    3
Lancaster III    0    1    0    0
Mosquito Mk VI    0    1    0    0
N1K2    0    3    3    0
P-38G    0    1    0    0
P-38J    0    1    0    0
P-38L    0    2    0    0
P-39D    0    0    1    0
P-47-D11    0    1    0    0
P-47-D40    0    3    0    0
P-47N    12    1    0    3
P-51D    4    8    4    0
SeaFire    12    1    1    10
Sherman VC    2    1    2    2
Ship Gunner    3    0    1    0
Spitfire Mk I    0    1    0    0
Spitfire Mk V    0    1    0    0
Spitfire Mk VIII    0    2    0    0
Spitfire Mk XVI    11    11    0    2
T-34/76    0    1    0    0
T-34/85    0    1    0    0
Ta 152H    2    0    0    0
Tempest    3    0    1    1
Typhoon IB    0    1    2    0
Wirbelwind    4    1    2    2
Yak-9U    0    2    0    0
     86 Kills    31 Deaths
....Now I am not a trained statistician, but there are a couple of k/d ratios that stick out right there for me, especially when you consider I have used the SpitXVI and La7 exclusively for desperate base defense while pissed off and flying like a lunatic, instead of in a cool and predatory manner. Gentleman, I am not that good. The plane does make a difference. I'm not 100% saying they must be perked, I am saying there is some reason to the idea of perking them.
As to OPs idea though...all I can say is damn yer eyes if you think I ought to have to pay more perk points to fly X because I've been paying to play this fine game for awhile. I'd cancel my account if they slapped me in the face with something like that.