Adobe - Does It Make Sense To Invest In This Company?

Adobe (ADBE) is a software company demonstrating a $47 billion market cap. Its main product, Creative Cloud plan, used to deliver big and fast-growing revenue. Generally all looks good but, in my opinion, for many years this company has been seriously deteriorating. Please, look at the chart below:

As the chart shows, since 2008 Adobe's cash margin percentage has been in a steady decline while the company's share prices have been in a furious upward trend.

Note: cash margin percentage is defined as cash flow from operations (excluding working capital issues) divided by revenue. If, for example, cash margin percentage stands at 35% it means that the company gets 35 cents in operating cash flow after realizing revenue of one dollar. 

As the chart shows, Adobe gets less and less cash from its sales. For example, in 2008 the company was getting 39 cents in operating cash flow from each dollar of sales. This year it gets only 25 cents.

According to the theory, the more cash a company generates the more it is worth. To increase its value, Adobe has to sell more and more.

Between 2003 and 2014 Adobe's revenue was growing at an annual rate of 11.16%. On the other hand, its cash margin percentage was decreasing at an annual rate of 3.4%. Therefore to sustain its current valuation the company must grow its revenue at an annual rate of 15.4%. Well, it is not a simple thing - since 2012 Adobe's annual revenue went down from $4.4 billion to $4.1 billion in 2014.
I see this company in black color...