I disagree wholeheartedly.
This game having easy execution overall has nothing to do with the fact that Karin has hard combos vs. the rest of the cast.
Ken has st.MK, probably the 2nd best whiff-punishing normal in the game (aside from Mika's f+MP?), that's EASYILY hit-confirmable into the crazy kicks TC xx HP SRK for effing godlike damage range-wise, for the amount of resources used (none). Even if you can't hit-confirm it from max range, which you should be able to by "spending 10 minutes practicing", it's only -6 which means most of the cast can't punish properly without meter or what have you. You can also cancel it into ex Hado to be plus on block.
Only hard hit confirm Ken has is b.mp into Chin Buster 2nd TC. Guess what tho! You can cancel this too into ex Hado to be plus on block and in their face! Don't forget that you can also link it from st.lp or cr.mp which makes it WAAAAAAAAAYYYYYY easier to Hit-Confirm.
Finally, Ken has cr.mp, st.HK (mid-hitting CC that can combo from anywhere if it hits, also can link into cr.HP if VTCed), st. HP (9f CC mid-hitting move only -3 on block), air Ex.Tatsu (braindead tool to get in by using 1 bar), normal crossup air Tatsu that can launch into a combo, meaties that beat 3f normals from ANY KD barring backthrow (unless corner), TONS and TONS of Damage/Stun when in his never-ending V-Trigger state and gimmicky (but safe) tatsu knockdown setups. Try AAing his Triggered air tatsu and get comboed into over 400 stun for a plus on block aerial move that has no hurtbox.
Yeah, Ken is really hard to win with........
I also don't agree that Cammy and Ryu are easy to play. As the level of competition rises, they become progressively harder to win with. Not that they aren't good characters! IMO they're both top 6 (Ryu being no.1 and Cammy somewhere around 5-7).
I believe the easiest characters to play currently are:
1. Birdie
2. Necalli
3. Nash/Ken (can't decide, honestly...)