Apple viewed Flash as non standard, and riddled with bugs. In this, they were right. Unfortunately, over half the internet insists on using this non-standard bug ridden product to produce interactive web content, and users don't have a say in the matter.
Apple said that they wanted web designers to ditch Flash and use the new HTML standards that did more or less the same thing. Until this happens, the Ipad remains a niche product unsuitable for much of the internet, and requires bespoke non Flash based versions of websites to be produced. Web designers are not all prepared to do this for the minority of users than insist on only using an Apple product for general internet content.
The strength of the iPad is the apps store, one of the biggest selections of apps, some free, of all tablet devices.