I don't so much hate it as resent having to install it just to play Mass Effect 3. It's not like I had ME 1 & 2 on Steam, I have all 3 games on good old-fashioned discs, so I can't really get arsey about swapping platforms. My gripe was that I wasn't going to download the game, just the DLC, and so why should I be forced to download Origin just for that? ME2 DLC didn't require me to go through Origin - the BSN handled it just fine. The download speeds are also a lot worse on Origin.
To me it smacked of EA saying they will take their ball home and not let you play with it unless you do it their way, which is desperately childish and I can't beleive that no-one at EA noticed this...not that they'd care! Steam was "pushed" on me in a similar way in that, when I bought Fallout: New Vegas, all the disc did was allow me to install Steam and download the game, which I thought was as mad as Sarah Palin on LSD. However Steam was popular, worked well and considering the alternative was Games for Windows: Live (which is what handled the achievements for Fallout 3), not the worst thing that ever happened to me. I never used GfWL as anything but an achivement-logger for FO3 and GTA4 and a means to get occasional game updates / patches. I did, on occasion, look through what games were on offer but none floated my boat. Not that I knew it at the time but, when I got my X-Box 360, my GfWL achievements transferred over, giving my gamerscore a little bit of a bump-up, which was nice.
Despite my misgivings, Steam has proven to be much better than GfWL and Origin. My catalogue of games is pitifully small but I have more downloaded games than hard-copies, the achievements track and I use one or two other little features that GfWL and Origin don't have.
Actually, now I come to think of it, because I only use Origin because I have to if I want to play ME3, I have just realised that it's more useless than GfWL in that it doesn't even track / register achievements - the game does that - and that pretty much says it all!
Finally, when I am finished playing ME3 and, as I invariably do, leave Origin running in the background, it is utterly unobtrusive...right up to the point I tell my PC to shutdown or restart. What happens is that Origin pops up, syncs up and then exits...and seemingly vetoes the shutdown / reboot command, which means I have to ask my PC to shutdown / reboot again.
Now this might be a perfectly innocent glitch, which has been overlooked and it's not like it's a massive irritation anyway, unless I forget it happens (which I do - a lot!) and end up leaving my PC switched on while I go out (I hate to waste power). However, because of EA's attitude, the way they handled my previous complaints to them (I.e they didn't), the spyware thing and their forcing of Origin upon me, I think it's their passive-agressive, sulky-child attitude manifesting in their software to remind me that I am a lesser mortal. I've been forced to play with Origin, even though I didn't want to, and when I say that I don't want to play anymore because I want / need to do something else and I am going now, it stamps it's feet, sticks it bottom lip out and pushes past you to get to the door, which it then slams in your face.
If all that were not enough reason to resent and dislike Origin, consider this. If a person acted in the manner outlined in the previous paragraph, you could retaliate in any number of ways without losing out (unless you took it a bit too far and wound up in The Nick!) but with Origin, you can't. Uninstall it and you can't play your games or access your DLC; complain to EA and they will cut you off.
For me then, that means I am stuck with Origin.
Great.