Carl Icahn has thrown in the towel in his quest to force Apple (AAPL -0.12%) to return more of its money to shareholders, even if the billionaire activist investor is celebrating the move by performing a victory lap.

"We see no reason to persist with our non-binding proposal, especially when the company is already so close to fulfilling our requested repurchase target," Icahn writes in a letter to Apple investors this morning.

What triggered Icahn's change of heart?

Apple CEO Tim Cook's revelation to The Wall Street Journal late last week that the tech bellwether has spent $14 billion on share repurchases since its poorly received quarterly report sent the stock lower could have played a part in the decision, but it didn't seem as if it would be enough for those following Icahn on Twitter.

In other words, Icahn was still egging Apple on to make more repurchases after that massive buyback. This then leads us to Institutional Shareholder Services siding with Apple over the weekend in light of Icahn's now-abandoned proposal.

That was the dagger. The well-regarded proxy advisory firm may have agreed with Icahn that Apple has been slow in returning its growing stash of greenbacks to its stakeholders through buybacks or dividend hikes, but it ultimately backed Apple in its actions. 

Apple didn't come to amass this country's largest market capitalization and its largest cash hoard by listening to the advice of outsiders. It's been pretty successful on its own, even if the past few quarters have proven challenging.

Icahn compares Apple to Google (GOOGL 1.79%) in his Friday tweet, but that's not fair. Google trades at a higher operating profit multiple because it's the one growing considerably faster. Besides, what was Icahn doing comparing Apple to Google? The search engine giant doesn't pay a dividend and it hasn't been as aggressive as Apple with stock buybacks. It defeats his argument that what Apple needs is to return money to its stakeholders to command a loftier valuation. 

In fact, what Google's performance proves is that Apple is better off investing in growth -- not buybacks -- to get back on track. There's nothing wrong with buying back shares to inflate profitability on a per-share basis. There's nothing vile about boosting its yield to attract income investors that will likely hold the shares longer than growth investors. However, if Apple wants to command the multiples it did in its prime a couple of years ago, it's going to have to be growing faster than it is right now.

Apple knows this. Icahn may have been successful in drawing attention to Apple's massive cash levels, but the better use for every dollar that it doesn't need to repatriate is to put it to work on needle-moving investments. Thank you for giving Apple some breathing room to do exactly that, Icahn.