Why all the traders use the same timeframes?

I am sorry for a newbie question. Why most of the trade terminals use 5, 15, 30 min, 1H, 4H timeframes? Why not 10, 20, 40 min, 3H, 6H??? Why all the terminals respect particularly these timeframe numbers (5,15,30 min, 1H,4H)???

Shhhhhh..........Its a "conspiracy" to give the Pro's an edge over the retail crowd....

......any other opinions?

It's probably not so much about Using as it is about Utilizing.

Even on my Monthly Chart Trades I will look at a 15 & 5 Min Chart in an attempt to improve my entry.

I guess what I'm saying is; make sure you don't get too close to the blackboard and always have a view of the big picture while trying to optimize your Entry into a Trade.

PS. Same goes for Exits but, of course, exits carry much more cargo.