That's just completely faulty logic for so many reasons:

a) Future value is not equal to current value.

b) $10M exit in the future is not set in stone. It'll take longer and be more painful than you think it will be. The chances that you'll have a $10M exit are low. You're doing well if you're pocketing $1M.

c) People won't fund you for free. You're giving up a chunk of your company. At 20% of $10M, that's $2M you're giving up. If you're getting more capital, you can expect to give up more.

d) Having full control and agility is more important than most people realize unless you have some really smart entrepreneurs who are your investors guiding you.