It's less harmful than alcohol in excess, but more harmful than alcohol in moderation, just as cigar or cigarette smoking is more harmful than alcohol in moderation.
You aren't going to parminently harm your body (or harm it at all in most cases) from consuming alcohol in moderation (ie in amounts that your body can fully metabolize at non-toxic levels), but smoking to any extent is harmful in a number of areas.
Of course, you don't have to smoke it.

(baking+ingesting it eliminates that issue)
Also hemp is legally used in the US too, just not the varieties with significant amount of certain chemicals present (namely THC), it's not very common though. (you occasionally see hemp twine around) It's rather limited in use for certain things, and not always more efficient than alternatives in the roles it is used. (honestly there's MUCH better aread that we could be focusing on in terms of alternative resources)