As you might imagine, the functionality afforded in your tool will define your judgment of Web analytics difficulty. When you have the ability to collect data the way you want and report data the way you want, Web analytics becomes easier. When you can't, it's hard. When you want to integrate data from internal systems, third parties, or qualitative studies, it can get complex.
Yoursite. Some sites are harder to instrument and more complex to analyze. Sites within the same company can vary in their user experience, backend architecture, information architecture, functionality, and goals. Sites, such as craigslist, still focus around the paradigm of a page view, whereas other sites have moved to rich internet applications (RIA) and AJAX functionality where the page view is largely irrelevant. Some sites make use of widgets, video, and provide mobile-only functionality. Certain more "rich" and "web 2.0" sites make data collection and tagging implementation and instrumentation hard and complex, while more static page-view driven sites are easier to instrument.
Your company's requirements. How your company decides to use Web analytics and their goals for the data impact an analyst's assessment of whether doing analytics is hard. All companies have different analytics requirements. Some companies regulate analytics to the discipline of marketing and emphasize the importance of using the data for campaign tracking and optimization, reach, frequency, attribution, and landing page optimization. Other companies seat analytics in product development and emphasize the data be used for functionality assessment, error detection, and overall usability analysis. Still other companies use analytics for ecommerce, and look at shopping cart performance, funnel analysis, and product performance. Other companies want to understand how specific visitors behave on the site and identify their propensity to convert to leads. Analytics can even be nested in a research group. Some larger companies have all these requirements and more.
Your team's skill sets. Not all teams were created equal. Some companies choose to homegrow Web analysts and give them training. Other companies choose to homegrow and say RTFM. Certain companies hire skilled analysts with years of experience at other companies. People with backgrounds in database marketing, business intelligence, financial analysis, business analysis, systems analysis, or even no analysis (entry-level) can be on an analytics team. Some analytical teams require only skills with Web analytics tools. Other teams require people to have skills with Customer Experience and Voice-of-Customer data. While certain teams need people who can create custom, proprietary tools around web data residing in internal databases. The often varied and sometimes motley skill sets of web analysts dictate the how difficult or not it is to do the job required by the company.
Yourprocesses. Successful Web analytics teams have defined processes for performing critical activities, such as collecting data, requesting reporting and analysis, and investigating data anomalies and discrepancies. Regardless of process, there is always a certain amount of chaos that revolves around Web analytics: the site is always changing; the reporting requirements can constantly shift; yesterday's site goals have largely become irrelevant; your tags have been pulled off the pages. By placing process around the chaos, the job of a Web analyst can become easier.
At the end of the day, is Web analytics easy, hard, or complex? I would argue that it depends on a combination of the factors I've presented above. There is no simple one-size-fits-all answer. So what do you think, good reader?