Should a startup co-founder worry about patents?

Shouldn't the first question be whether you have "invented" (not just agile-dev'd into a MVP) something worthwhile which is truly non-obvious or not already implemented elsewhere? Software products also tend to be harder to patent since too many skirt too close to the abstract idea. Given that most issued patents are held by incumbents with money or market gorillas, perhaps the better topic to address is how to avoid getting involved in patent infringement in the first place ... recent rulings on copyrights show that implementing similar functionality is allowed under copyright idea/expression dichotomy so if you are looking for a defensive measure, you better think hard (eg tradedress for the UX).