With its stock plumbing new lows and fresh off a disappointing quarter, Apple  (AAPL) - Get Report  CEO Tim Cook may be hearing the critics of his stewardship of the tech giant nipping at his heels.

But getting too wrapped up in the views of the often short-term minded Wall Street and possibly taking the eye off the long-term may not be a wise move for Cook, says Apple's former chief.

"I think he (Tim Cook) just needs to stay focused and ignore it (the criticism)," said former Apple CEO John Sculley in an interview with TheStreet, when asked how Cook could regain the confidence of skeptical Wall Street.

Sculley, who served as Apple's CEO from 1983 to 1993 and is familiar with the external criticism inherent to a business created by a legendary founder (Steve Jobs), added, "He is the same Tim Cook, a very experienced CEO with great judgement --  I am very much in Tim Cook's camp, and think Apple will do just fine."

It's not too hard to see where the stock market is coming from, however. The tech giant reported fiscal second-quarter earnings of $1.90 a share on $50.56 billion in revenue. Wall Street expected Apple to deliver earnings of about $2 a share on $51.97 billion in revenue. Revenue plunged 13% from the prior year, representing the first quarterly sales decline since 2003.

Apple's cash cow in the iPhone saw a unit decline of 16% year over year, marking the first unit drop ever for the popular smartphone. Units for the iPad and Mac fell 19% and 12%, respectively, from the prior year.

The iPhone unit decline spurred concern that Apple was losing its competitive edge in the slowing smartphone market, and would be forced to drop prices to reignite sales.

Meanwhile, Wall Street has turned sour on the long-term prospects of the Apple Watch -- the first major product release by Cook -- reasoning it's more of a niche product than something transformative. Further, investors have grown concerned the company has lost its innovative prowess and will unlikely introduce a game-changing product this year.

Apple's shares are down 11.5% so far this year compared to a 4.5% decline for the Nasdaq Composite. Over the past year, the stock has lost roughly 26%, despite Apple continuing to generate impressive sums of cash and shell out money on otherwise shareholder friendly dividends and stock buybacks.

Even in the face of such uncharacteristic doom and gloom, Sculley believes Apple does have several upcoming catalysts ahead that could reignite investor confidence.

"Just refreshing the installed user base of the iPhone is going to be huge, the iPhone 6 was successful and I suspect they have an iPhone 7 coming that will be just as successful," said Sculley, adding the Apple Watch will likely catch an update that un-tethers it from the iPhone.

Concluded Sculley, "Apple's business will be back up and Tim Cook will be a hero again."

Added Jim Cramer and Jack Mohr of Action Alerts PLUS in a recent note, "We remain confident in Apple, and will continue to hold this name for the long term -- Apple isn't simply a hardware company, it is an ecosystem that engenders long-term loyalty and constantly innovates on behalf of its customers."

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