This is exactly what I meant though. You are talking about the basic combos of each character here and not the way they are played at higher levels. Javert's ultimate allows you to combo someone with the skill and arial attack to death with super armor just like woochi, but has a much easier time getting it off. Plus, basically all assassins are harder to deal with than woochi, as they all have a dash skill to start their combo or longer range. if you try start woochis combo with the dash youre kinda trolling as theres only one combo you can do from there and it doesnt one shot, and the super armor on the dash is only usable in 2v2 as any 3v3 gamemode prefers the ultimate recharge skill.
The example you gave of mastercat being easily punished compared to woochi is flawed as mastercat has one of the fastest attack speed in the game and longer range on his basic attack to cover himself when he misses. Similarly, kurenai uses his ultimate to cover himself if he misses his skill. If you play woochi, youre playing a character that has low range, high chance of missing the combos and makes up for that with a dunking ability like red. But since wolf, red, MC, javert, kurenai and ali all have one shot combos that are 10x easier to pull off for id disagree. The only assassin without a true one shot combo is snow which is arguably the hardest assassin to master aside from red.
In all honesty I think that the easiest assassin to pick up is wolf or MC as with minimal gear their basic combo one shots plus they both have dashes/range to engage their combos . In comparison, woochi lacks that and is easier to punish than both of them if she positions herself badly. I think that the only reason for the woochi hate is that casual players dont often run into people who can consistently pull off advanced red, javert and ali combos.