Yes, but if the company is treating you badly, you don't owe it to your coworkers to continue enduring that for their sake. If they really value their professional relationship with you and if they respect you, they will certainly understand that you can't be expected to subject yourself to two additional weeks of poor treatment just for their sake -- and neither should you expect that from them if they determine that the company is treating them badly and they need to quit.

It is not you who has made the coworkers pick up extra slack via your choice to quit without notice. It is the company that has given them that extra burden by placing you in a situation where the only healthy option was to quit without notice. Thoughtful colleagues will understand that the company is to blame for this kind of thing, not the worker who did not give notice.

In cases when someone was treated well and simply did not give notice for some extrinsic, selfish reason (like being offered a sign-on bonus to start immediately at a new firm or something), it will be pretty obvious to everyone that actually the company had treated them well.

Right point.

The higher skill a job requires, the less impact quitting without notice should have on colleagues, with respect to "pick up the extra slack." As far as I can tell from reading around, it's going to be a long time after even a two week notice before a replacement is in place (if at all).

You should probably send emails to people about what's where, etc. Or try not to have loose ends. And I can understand colleagues feeling snubbed without a goodbye, much less a happy hour.

I'm not advocating without notice, but when it happens, around "here," I just don't see much of an impact.