Those 4 "scrubby" characters are what they are for two reasons:
a) PL already stated it: they punish you for *gasp* blocking. Yes, chip damage is part of MK, but to be in a situation where if you block you lose or if you get hit you lose is moronic. Kenshi is the lesser evil of the 4 because his chip can't kill you as bad as the others. The order they rank up in this aspect is: 1. Cage, 2. Kabal, 3. Sonya, 4. Kenshi
b) Unlike the rest of the cast where you only have to guess or make a read from 2-3 options, this top 4 characters have an array of options beyond 4-5. At the heat of the match, where every move counts, making a read from so many options is a gargantual task. Let's take a rough look:
*
Cage: F3, F33, F33B3, D3, 11, 11F1, 2, 21 (with
Force Ball to mix things up).
*Kabal: F3 2 NDC, F3 2 Hooks, F3 2 Saw, F3 NDC, B1 NDC, B1 2 NDC, 111 NDC, 114 Hooks, 114 Saw (I might be missing some).
*Sonya: 114 MS dash, 114 MS dash grab, 114 MS dash 114, 114 MS grab, 114 MS sweep, 114 MS F1, 114 MS F1 Cartwheel, 114 Cartwheel, D4 Cartwheel, D4 MS dash, D4 MS dash F4, D4 MS F1, D4 MS F1 Cartwheel.
*
Kenshi: TF, SC, RK, TK Slash close, TK Slash mid, TK Slash far,
SC, F3 2 RK, F3 2 SC, F3 2
SC; Kenshi still is the lesser of the 4, but those options practically build a wall infront of him.
In sum, sick shit.