That said some sites do run without archivelog mode enabled but the big difference is that its a proper decision and they know the consequences and also know how to get all their data back. This is sometimes a solution in data warehouses.
Also don't forget that there are some tools available that can help open a corrupted database and get some data out of it. Oracle has the Data UnLoader (DUL) tool. This is a tool closely guarded jewel in Oracles crown and if you have a crashed database and no other way to get the data out then you can call Oracle in to help with this tool. There are at least a couple of private tools out there that can be used as an alternative, one of which i will tell you about in a post tomorrow.
I have just added a couple of links to my Oracle Internals page about Data UnLoader (DUL), one is a link to the user guide for DUL and another link to a post about its use and some examples.