There are chances that people might lose interest in Bitcoins, or might there happen something like a big pump that could take BTC to somewhere that will drag everyone's attention towards it again...
Well with the price 450 USD and having a Antminer S7 + a energy rate of like 10 cent / kW the ROI period is less then 120 days. It's a little bit high yes but 'doable' even more if you expect the price to rise even more.
But looking towards the difficulty that skyrocket big time see:
https://bitcoinwisdom.com/bitcoin/difficulty
It's very risky again. Therefore i wouldn't advice to buy mining gear right now.
Because if u are, then it will be profitable for me so then I am very interested.
he forget diff, but right now a s7 can earn you a nice profit, and consumption is around $45 per month with 0.05, with 0.1 is double that
earning is $360, but the next diff jump will put us on another +10% or so, still plenty of room for profit
But difficulty jump ain't just one thing, halving is another and the price is the most considerable topic to be focused when it comes to mining, as buying for least BTC at higher prices might look good, but even if you get that ROI in BTC in 6 months and the price is slashed 50% down, then I guess it's double your wait to just gain your ROI in full, I mean the one will need to wait a year instead of the mentioned 6 months...