Just because people lose passwords is not an argument against encryption.
There is plenty of people who do not lose passwords and I'm pretty much sure majority of them does not lose it.
You just happen to deal with people who do, but those who don't lose passwords don't come to you and tell you, hey I didn't lose my password, so your argument is biased based on a group of people who came for help.
I would say it is an arguement against it on individual systems. corporate and places that keep information from many people or places, it is good thing. Those are handled by professionals. but on ordinary everyday people's systems it has caused more heartache than good. As pointed out, the encryption on a drive is pointless once you are signed in, and if somebody accesses the system while you are signed in, then it does no good at all. The average person is under the mistaken belief that encrypted drives keep everybody out. Then they find out the hard way that they are the one kept out when the system needs repair or if you need to recover data on the system when it is damaged. I doubt you really need to encrypt your photos and letters to mom etc.
on a system governed by hippa or banking regs it is something good.
on a personal system it is not.
If somebody is looking to steal personal information they target one place such as a bank or hospital. They do not target hundreds of individuals because it is not efficient to do that. Think this way. A smart thief does not rob hundreds of people for $100 each. he goes after the bank and takes $40,000 at a time.
In my company, we do not use encryption. at least not whole disk. we use proprietary encryption on just the private data. This means that in a disaster, we can access the drives and recover data but can't read the sensitive files unless we have the software for the encryption of those. Every week I get people come in unable to recover data due to encryption they put on. So far only one had the keys saved and retrievable. All the others lost everything and learned the lesson the hard way. You can argue all you want about good bad and don't lose keys or passwords. But the average person will lose them. Then they think that the professionals can hack in like on TV.
Oh and in answer to people that don't lose the password not telling me they are still ok, Compare that to 300,000,000 people not telling you they are fine so that means the 4,000,000 that died should be ignored. The fact it is so frequent should be enough of a sign that you should pay attention to the issue.