What's the thinking in this big raise ?

Why would this villain make such a big raise ?
PokerStars - €0.05 NL - Holdem - 9 players
Hand converted by PokerTracker 4

CO: 131.8 BB (VPIP: 23.19, PFR: 4.01, 3Bet Preflop: 2.93, hands: 943)
BTN: 25 BB (VPIP: 12.12, PFR: 6.06, 3Bet Preflop: 0.00, Hands: 34)
SB: 32.2 BB (VPIP: 52.17, PFR: 4.35, 3Bet Preflop: 0.00, Hands: 24)
BB: 100 BB
UTG: 41.4 BB (VPIP: 0.00, PFR: 0.00, 3Bet Preflop: -, Hands: 3)
UTG+1: 100 BB (VPIP: 7.22, PFR: 6.19, 3Bet Preflop: 3.57, Hands: 195)
UTG+2: 100 BB (VPIP: 9.65, PFR: 5.26, 3Bet Preflop: 0.00, Hands: 229)
MP: 40 BB (VPIP: 17.24, PFR: 16.09, 3Bet Preflop: 10.00, Hands: 87)
Hero (MP+1): 125.2 BB

SB posts SB 0.4 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.4 BB) Hero has J:heart: A:heart:

UTG calls 1 BB, fold, fold, fold, Hero raises to 3 BB, CO raises to 16 BB, fold, fold, fold, fold, fold

CO wins 8.4 BB

Isolation moves...

One possible explanation is that at low levels, there are players whose calling ranges are quite inelastic. This means that they will call a fairly wide range of raise sizes with the same hands. So, if the 3bettor is looking at AA or KK and thinks there's almost the same probability you will call whether he makes it say 9bb or 16bb, why not make it the higher amount?