Growing account from $100?

So, what is all this skepticism on the internet about people asking, "Can I grow my account from $100 to $10k in 12 months?" The answer is usually, "No, you can't," or "You need a bigger account," etc.

If you take a calculator, start with $100 and double it every day (so only $200 instead of $400 a day like you've been doing) you'd have $3,355,443,200.00 by the end of the year (approximate as I've counted for 200 "trading" days).

I believe $100 to $10k is even doable in about a month.