A "lock" in programming generally refers to a mutex, semaphore, or similar mechanism implemented mostly in software, e.g. see here https://en.wikipedia.org/wiki/Lock_(computer_science) . The distinction between such locks and atomic instructions is useful, since atomic instructions have various nice properties that locks (or "other locks", if you want to count atomic instructions as locks) do not, such as having no chance of deadlocks, guarantee of (eventual) progress, no chance of interruption, and no chance of blocking other threads forever when a thread executing an atomic instruction gets unlucky and is never scheduled again.
Naturally lockfree algorithms built with atomic instructions may not have (all) of these nice properties.
What better name would you suggest for lockfree algorithms?
If you're being pedantic, atomic instructions are a misnomer. But "Lock free" is a property of parallel algorithms where if there's N > 1 processors evaluating an algorithm, there is no state where the algorithm cannot make progress ("locked" meaning "all N processors are waiting")
Whether you want to debate if a physical system can realize a lock-free algorithm is a different debate. Hell, half the "well known" lock-free algorithms assume memory allocation/reclamation isn't blocking.
