Not necessarily disagreeing with you but let me give some counter arguments:
1. If you have a small account, commission and slippage are huge hinderances to your profitability as a trader. For argument's sake, lets say each trade cost $10 in commission, a round trip would be $20. If your account is $1,000 and you make one $1,000 trade a day, the commission will be 2% of your account and if you consistently make 2% profit a day, you barely breakeven. For an account of $100,000 and you make a $100,000 trade, commission will be .02%. If you make 2% a day, your profit will be ~1,660% a year, compounded daily, or you make $1,560,000. So, size does matter.
2. The other argument for a larger size account is drawdown. In the small account drawdown is a bad downward spiral, if your account is reduced to $500, a $20 commission will be 4% of your account. It is very hard to consistently make 4% a day but for that you just breakeven.
3. Limiting your trade to 1% or 2% helps avoiding huge drawdowns. For a large account, trading 1% to 2% makes sense because 1% of $100,000 is $1,000 and you can buy a decent option contract for that amount each trade. For a small account, 1% means $10 hardly enough to pay commission. So, account size matters in keeping the trader's account solvent.
4. In a large account, you can afford to make "conservative" trades and still make a decent profit. For a million dollars account, a 20% annual profit will provide a decent return whereas in a $1,000 account you have to take big risk to make a dent.
My view is a minority view here at ET but IMHO, if you just start out, it is better for you to save up enough for a sizable account before you start trading.
Regards,