Yes, when you buy STEEM you basically buy the time you would normally spend blogging (and earning STEEM). But it's a shortcut because you don't build your account (followers, rep, relationships).
I have done a combination of the two (blogging and investing).
@exyle I think this is the way too. I wish it was easier to do for people relatively new to the crypto space. Nonetheless, I am going to be doing this as well. Great idea.