When a modern startup at a pitch says they will build a web service and target tablets in development, I immediately understand their level of expertise.
No matter how much Apple promotes their tablets, they are a niche product: about 90% of users use them as portable YouTube players, another 9% as graphics tablets. The remaining 1% are browser users. This is easy to notice if you have actually built websites and added a traffic counter.

Moreover, the percentage breakdown is roughly the same across all sites where I have access to statistics. And these shares have not changed for several years.

Why doubt their expertise? Well, who would focus on 2% of users and even bring that up to investors?