Hi Tommor!
Thanks for the post! 
This question of day-trading v. multiday/week trading would indeed be a useful topic for discussion, and I think there have been threads about this before, but whether it belongs here or not, I don’t know 
Whilst I wouldn’t be surprised if many starters did fail after just a few months of day-trading, I am not so sure that it is inevitable or simply due to being “daytrading” per se. Personally, I think day-trading is very intensive and demands a strict discipline, sharp concentration, and an ability not to rationalise moves! The benefit, of course, is that one is trading when one wants to and is flat whenever not trading. Day trading does not need to mean all day. I tend to ignore Mondays and Fridays, and even on Tues -Thurs I only regularly focus on 3-4 hours of NY time, unless there is something special happening at other times.
Perhaps the biggest difficulty with day-trading is knowing when not to trade! The tolerance regarding entry and exit is very tight and there is a strong benefit from pre-empting the next move rather than reactively chasing the market. Either way, I agree that it can be fraught with danger and an inexperienced beginner can lose a lot very quickly - and destroy confidence.
On the other hand, I could imagine there are also difficulties of a different kind for a beginner setting out to trade, say, daily charts. Would you not agree that, for example, sensible stop positions can inevitably mean big potential losses which may be difficult to justify with a very small equity and I am not sure how much education one would get from watching just one position for many days?
I realise that there is a lot more to be said about daytrading, swingtrading and positioning. There are pros and cons with all of them. But maybe the common denominator with all three approaches is that success is more likely to depend on one’s own dedication and willingness to study and learn as well as a readiness to devote at least the same degree of time and effort to it as one would to any other profession?