Big rewards with small bet amount is the simplified version of what gambling does to attract customers and the gambling itself has long history with human kind like atleast 4000 years so we were used to the system and only thing is evolved according to the current people needs.
I agree that many gamblers were drawn to gambling because of the winnings of other gamblers. Most people do not care when such a gambler started gambling or what challenges he or she faced; instead, their minds are preoccupied with the fact that there was a large winning, and they conclude that they, too, can be winners.
No clock, no windows to make people not realise how much time spend is one of the common practice to give immersive feeling but we don't have smartphone to find out the time?
Even when a concerted effort is made to keep time, it still requires discipline. No clock will compel a gambler to leave a gambling house if the gambler chooses not to obey the alarm. So it is possible to set an alarm and not follow it, as well as to not set an alarm but still be conscious of time. So, what matters is not the clock, but rather self-awareness.