The phrase "a simple justification for" is correct and usable in written English.
It can be used when you want to explain or provide a reason for something in a straightforward manner.
Example: "The report provides a simple justification for the proposed changes in the policy."
Alternatives: "a straightforward reason for" or "an easy explanation for".
* * * Big Pharma has a simple justification for charging high prices for drugs: it costs a lot of money to invent a medicine and bring it to the market, so the prices have to be high or the companies will be unable to afford to continue their important research and development (R&D).
He offers a simple justification for the work: "Cell populations are heterogeneous.
A simple justification for PCA is that by choosing the linear combination with maximum variance we are retaining as much of the information contained in X it, i = 1,.., k as possible with the use of only a single variable Z1 t.
The "determination rule" analysis provides a clear and simple justification for analogical reasoning.
The attacks of 7/7 and the gruesome events in Woolwich were the products of marrying young men already drowning in their own grievances with a moral code that provides simple justifications for employing the worst excesses of human capacity.
There was a simple enough justification for the decline.
The following brief postscript to the paper offers a simple graphical justification for the claim and discusses the implications.
This is arguably the most disturbing of insights from an examination of global energy-use trends, and a simple, clear justification for a political prioritisation of the issue.
A simple theoretical justification of the empirical results for the flow velocities required just to suspend solid particles in horizontal pipes is deduced from turbulence theory.
But training materials for XKeyscore detail how analysts can use it and other systems to mine enormous agency databases by filling in a simple on-screen form giving only a broad justification for the search.
But simple embarrassment is not a justification for suppressing the truth.
