1. If you're not there, someone else is. If Nike didn't buy brand terms, adidas would and would steal tons of customers.
2. Paid results (and other results like maps, shopping, etc) often push organic results below the fold so no one sees them. You need to be above the fold.
TS using "Squarespace" as example, not "web shop".
Google loves branded Kws on Adwords. Bidding on competitors will have a low quality score, but drives up the competition for the brand owner. With all of the above the fold distractions, you basically have to pay if you want to be above the fold.
Source: https://support.google.com/adwordspolicy/answer/6118?hl=en