even with cheap electricity, you have to keep in mind, that he will have to secure the space (or rent something), take care about cooling during summer, noise, internet connectivity...bla bla...
and all this suffer for doubtful ROI. sorry, but convincing guys with 120$ USD budget to mine is just stupid. I mined for last 3 years with all available and believe or not, but mining is not only about electricity cost.
I don't think anyone here is trying to convince baristor to mine; people are advising him on what to expect if he decides to do so, whether or not the price of the miner is favorable, what costs he will incur in, how to make those calculations for himself, and so on.
Now, you bring up a good point: space, cooling costs, noise - no one else brought these up, and they're important (certainly something he would need to plan ahead for); but maybe you should have started off with that, instead of pointing him to the increase in difficulty (I certainly still have a lot to learn when it comes to mining, but it seems to me we will likely not be seeing the dramatic increases in difficulty we saw in the past again, unless some new far, far more efficient miner comes along and surprises everyone). Likewise, it's not very helpful to call him a troll, spammer, ignorant, or time traveler.