1)smaller time frame charts have too much noise, trends and analysis on a 4h or 1D chart are going to be far more accurate than that of a 1 or 5m chart
2)the moves you will be looking for will provide for much larger gains, when first starting out in trading, having to pay a spread on each trade will be very hard to overcome when the analysis is only allowing for a move of 10-15 pips before you take profit (you will be virtually on top of your risk tolerance straight out of the gate)
3)It provides you much more time to analyze a potential move without missing it. if your trade is shaping up on a 5m chart and you spend 15m analyzing the information on the screen, there is a very real chance of you missing the trade entirely...this can lead to chasing,churning,revenge trading, etc..all VERY VERY bad things.
Note: Unless your strategy is specifically centered around scalping there is no real reason to be basing trades off of a 1m or 5m chart.
Remember to always define your entries and exits, make sure to have 3 good reasons for entering a trade and do NOT force anything, its ok to miss a trade..there will be plenty more, and its always better to miss one wishing you had been in, than in one and wishing you weren't!
As always, feel free to contact me with any questions or for second opinions on any of you technical/fundamental analysis,