That makes no sense at all.

If for example you had $700 to spend, whether that was one share at $700 or post-split seven at $100, the price is the same in terms of what the shares are worth. And you'd have been better off buying one at $450 a year ago than seven now.
If you don't understand this you shouldn't be buying shares.
You are assuming that he would know that the shares would split eventually. For many investors (especially for retail), a stock with a price so high that you can only afford one (1) share makes it less attractive than another wherein you can buy multiple shares. Thus, people tend not to spend all their money on a single share of apple, seeing as even if the stock went up 50 points (which would be a huge gain in the stock market), they would only net $50 on an investment of $700. Makes it not worth the risk.
Now that people can afford multiple shares, the stock looks more attractive. And they need not have any fore-knowledge of any upcoming splits. I spend $700, and own 7 shares, and if each share were to climb $50 (very likely given the upcoming catalysts), I would profit $350 on a $700 investment.
This is why splits are advantageous, and why stocks that split generally outperform the market in general and are up many percentage points in the year following the split.
But you are right, generally speaking, that there is no fundamental difference between 1 $700 share of apple and 7 $100 shares, EXCEPT for the psychological advantage that $100 shares have, which results in many tangible benefits, and the very real advantage of having gains come in whatever multiple of the stock you are able to buy due to the lower price.
An real world example: AAPL is up $1.48 today. Had it been presplit, at 1 share ownership, you would have made $1.48 in profits had you sold your $700 share.
Post-split, say you owned 7 shares of AAPL: You didn't gain $1.48, you gained $10+.
Splits make a difference, and anyone that says otherwise doesn't understand a very basic principle of investing: it's better to own more shares when you can have those shares for the same investment as you would have had to make to buy fewer shares or one share.
And to say you'd be better off buying in at $450 a year ago is absurd wherein you are taking advantage of hindsight. Why stop there? I would have been better buying Apple back in the 90s. I should have just bought millions of shares and held throughout all the years. Anyone that applies this hindsight (especially when used to put someone down indirectly) has never invested in the stock market. Real investors know what it is like to watch a stock move throughout the day and not know precisely where it will wind up.