I would NEVER just upvote every post I see. First of all you would burn your voting power way to quickly. You should never use more than 20% per day.

One of the two main features o Steem is proof-of-brain which allows you to upvote the best posts in your personal opinion and therefor give value to them.

Yes, you DO have to post a lot. I wrote over 400 posts in seven months! If you are REALLY good and you network like crazy you can get successful in much less time.

Steem needs much more time to fully understand than learning to program software or get a super-memory with memory techniques. But it is certainly worth it.