I think the question you asked in the title should be "Is UPVOTING comments profitable?"
Because - as you said: "No/it depends", while upvoting comments have some value beyond monetary. It's a simple way of saying "I agree with you" or "Your comment is valuable", instead of writing that.
Which brings us to another subject... I think Steemit's best strength and weakness at the same time is money. Sure, it's a great idea to reward people with "money" for their content. Especially for Average Joes, who won't make a living from their stories, photographs, videos, etc., but on this platform get to know that they can produce something of value from time to time, at least. It's nice to know "Oh, I got 3$ for my blog post, instead of getting nothing at all".
At the same time treating Steemit as "means to get rich" is wrong. For three reasons: first - the value of STEEM/SBD is very low at the time; second - treating it as stock market with extra steps often leads to malpractice; and finally - we are ignoring community aspect of the platform. Steemit has great potential for bringing people together; creating both virtual and real-life projects.
i agree on most of your points.
not sure do you mean profitable for voter or commenter? i never thought about upvoting as a means of profit for me (i know it is), don't really care when it was published (in the 7 days period) or all that technicalities, if i like it i will upvote it.
the reason i wrote that if you can't upvote more than 0.025 the better thing to do is to check the commenters posts and if you like it, uprote that, is that is a way to find more about the person, strengthen the community and also monetary reward that person.
Getting rich on steem is well not really an option right now, and people should probably know that. it is a marathon and there is a chance that we will not finish it :)
In the "golden days" of steem i thought about it as a way to maybe pay for the fuel i will spend on some trips or something like that, now i am just sharing my photos :)