Just look at it this way you'd fit right in at PM
[mod edit] the above comment was deleted due to snark. Let's keep thing civil, guys!
I can't count the number of times I've heard negative comments about PM for the attitudes of some of their users. Comments run from members being arrogant, to all knowing, to others that shouldn't be repeated. Yet here we are seeing comments from some who detest this when being on the receiving end more that happy to dish it out.
Keep in mind this hobby like life has a learning curve. No one I know has all the answers to all the questions that might be asked. People that advertise machines and tools could be doing it for a variety of reasons. They could be attempting to help settle an estate, helping a disabled friend, unloading equipment they have no need for, interest in, or knowledge of condition bought as part of an auction lot, or a thousand other reasons.
The seller could make statements about capability, wear, and reliability if they knew them or if they knew how to assess them. If they don't have the knowledge or skills necessary to make accurate assessments it's best they don't. Over the years I've looked at hundreds of machines, and by far the vast majority avoid condition assessments as they know it's only their opinion. Ten people looking at the same machine could quite possibly have ten different opinions. The easiest way to get information is to message or call the seller. You'll know within seconds whether or not they have any knowledge of the history, condition, or capabilities of the machine.
If you have interest in a particular machine, and it's within a reasonable distance go and check it out. You might be pleasantly surprised. I've had several cases where the machine was far better than I expected. Had the owner posted that information it would have been hard to believe given it's age. Other times sellers have all but given away the machines. They knew they didn't want or need them, but also knew if they were to advertise it as "free to a good home" the ad would attract all kinds of undesirables looking to turn a quick buck.
Keep in mind how you felt the last time someone berated you for something as inconsequential as not providing ALL the information they thought they should get. When you put yourself in those shoes it isn't a good place to be. You will quite probably remember it for some time to come, and be reluctant to put yourself in that position again if you can avoid it. The next time your aunt, grandma, or close friend asks you to help selling something you may just decline to avoid a repeat of the same experience.