Restaurants rarely advertise "free unlimited napkins with any meal". They include them gratis, within reason.
Nobody can provide "free unlimited" anything. There are always limits. In Australia, these claims could run afoul of consumer protection laws, with good reason - anybody claiming to sell "free unlimited" anything is lying. OK, Linode probably means well. But before you know it, every company will match them, and you won't be able to figure out which "free unlimited" plan suits your purpose because all the limits are hidden behind a "within reason" clause in the fine print.
"Free unlimited" offers turn the whole thing into what Scott Adams calls a "Confusopoly", in which companies stop competing on value by hiding what value they actually offer.
Something similar has occurred with LCD monitors, all companies advertise stats that are grossly misleading like "dynamic contrast ratio" and "grey to grey response times", but sound similar to the legitimate measurements like contrast and response times.
These fake numbers are much more impressive sounding than the "real" ones (1:100000 dynamic contrast ratio (DCR), vs something like 1:10000 regular contrast ratio (CR), when infact the monitor with a 1:10000 CR could be greatly superior to the 1:1000000 DCR monitor, which may easily only have a 1:1000 CR), so companies that provide the real numbers are penalized in the marketplace, so instead start to only publish the misleading numbers. This has made it all but impossible to meaningfully compare screens on manufacturer provided stats.
Information asymmetry plays a powerful role in marketing, and can result in a race to the bottom where consumers cannot compare things in real terms before purchase, so providers have no incentive to deliver anything of quality (extra costs, no meaningful way to market the extra quality as an option). This sort of behavior is also extremely common in residential ISPs ("unlimited" internet always sounds better to the average consumer than some kind of published limit).
Yeah, at one time the US FTC cared enough to enforce honest reporting of CRT sizes back in the old days. Apparently they don't care about LCD stats though.
All they say is that no matter how much you use you will never have to pay for it (at least that's how I read it). Obviously they can't guarantee that they will be able to offer you an unlimited amount of inbound bandwidth (there is no such thing!). Do note that they make no guarantees about the speed of your inbound connection either.
The same goes for other things, of course. You can't necessarily get unlimited outbound bandwidth and you can't buy an unlimited number of servers from them and so on... Sure, those limits (both quality and availability) aren't stated explicitly, but I still think it's fair to say that "whatever amount of inbound traffic you use we won't charge you for it". In extreme cases they will need to do something, but there are other options. There's a certain value in keeping things simple and flexible.
I do agree, though, that hiding (important) limits is generally not a good thing to do.
Nobody can provide "free unlimited" anything. There are always limits. In Australia, these claims could run afoul of consumer protection laws, with good reason - anybody claiming to sell "free unlimited" anything is lying. OK, Linode probably means well. But before you know it, every company will match them, and you won't be able to figure out which "free unlimited" plan suits your purpose because all the limits are hidden behind a "within reason" clause in the fine print.
"Free unlimited" offers turn the whole thing into what Scott Adams calls a "Confusopoly", in which companies stop competing on value by hiding what value they actually offer.