In a way, this is an unfair comparison, since we are comparing the relatively hermetic Tableau with a product that has already split in two for lack of foresight. But what can we do? Qlik balked at the ground-up codebase rewrite, which might have been prompted by the advent of Tableau in the mid-2000s. It's now left with one package that has a semi-'legacy' status, and another more modern offering that perhaps omits too many of the powerful features of the original.
The long-term prospects of both frameworks are an additional consideration. The nature of the $15.3 billion purchase of Tableau by Salesforce suggests an evolutionary rather than predatory change of ownership. Yet, the ramifications of any potential corporate-led changes of direction or policy are still an unknown factor.
Against these challenges and the headwind currently enjoyed by Microsoft in the BI software space, there is also a raft of insurgent contenders looking to unsettle the old guard, including Domo, ThoughtSpot, ClearStory, and Looker, among others. If 'recent provenance' was the sole compelling factor, one would have to overlook both QlikView and Tableau!
But experience counts: QlikView and Tableau are known, productive quantities with a mature base of developers to draw from, and, respectively, impressive client lists; and each has fought for and won a precious vanguard space in a very crowded market.
If you need pre-optimized, highly responsive presentations and can commit to the extra scripting and diminished hand-holding that QlikView requires to achieve it (and the hardware upgrades that often become necessary when QlikView implementations start to scale), then this seems an apposite choice.
If your needs are more exploratory and less architectural, Tableau offers a flexible and powerful data discovery experience that can reveal new inter-relationships between data sources with the facility and flexibility of a framework that was primarily designed for this purpose.