because not everything you buy is being purchased for the purposes of immediately selling on for a profit.

If I bought say a floor sander as I was renovating an old house - I might only need it for one job - but it might be cheaper than renting one. But it was something I got use from, that was my personal possession that I can then sell on.

logically - ebay might want me to sell that again. ebay aren't clever enough though to differentiate between items that logically could be sold on again vs those that can't.

I don't really see the harm. It can be ignored....