Well, I can only speak for myself, but firstly let me say I don't hate Onepass or Continental.

What I hate includes some of the following *behaviors* of OP and CO - without these issues, I would consider my CO experience to be near perfect.

* having to jump through ridiculous hoops to redeem my miles at published rates
* having to dial around to a half dozen different agents to find out who knows what is going on, undestands the rules or has the slightest inclination to help me
* having to figure out a convoluted series of program rules that only Dr. Robert Oppenheimer could understand
* behind the scenes secret tinkering to make sure that certain passengers receive or do not receive published benefits according to a mysterious non-published logic
* many front-line agents who need a reminder that Elite members represent an important piece of the bottom line which keeps them employed, so they should think twice before treating us like something they found on the bottom of their shoe
* making any customer who didn't pay full Y feel like a cheap bum who should be sitting in cargo
* a coach class that was designed to fly a planeload of munchkins in comfort
* a negative attitude towards elite customers who fly on mixed or lower fares, like our money has no value or we should be discarded as customers
* the worst international upgrade program around - unless extortion and gambling are considered good things
* modifying the fleet to reduce the number of available FC seats so that there are only enough upgrades for high fare Elites or just enough to sell to full Y passengers - thereby removing a core benefit without having to say you removed or changed it

Personally, if I had to start over, I would fly NW or AA. If I flew 100,000 miles per year, I would now choose AA handsdown - unlimited free domestic upgrades, easy international upgrades, easy award redemption, dedicated agents for Elites, etc. etc...AA wins hands down.

If I could only manage 75,000 miles, then I would choose NWA.