I assume it was downvoted because out of most computers, old Macbooks seem to stay in use for the longest and also tend to get updates for a long time. Sure old PCs can run many lightweight linux distros (and so can old Macs), but OEM support from Apple for old Macs is something you hardly even see with other computers (maybe some business computers...).

I think that if you don't get locked out, they stay in use for a relatively long time and are also always sought after in the used market.