No, they are not.
If you want a decent recreational-level mtb that will actually be useable off-road and actually last, go to your LBS and purchase something from one of the 'major' mfgs. For example (there are others) Giant, Specialized and Trek all produce decent-quality bikes -- hardtails with functioning front suspension -- that will serve well for light-duty for a minimal outlay.
Example:
Talon 27.5 4 (2015) | Giant Bicycles | United States
If I were you, I wouldn't buy a used mtb off Craigslist unless/until I had developed some good ideas as to what to watch out for in the way of worn-out parts, cracked frames, etc.