I am not against people linking to their sites from Hive. You need to beware of being seen as spammy as the 'Hive police' could get on your case. You can always decline rewards. I don't know much about SEO, but having more content on Hive could be beneficial.

I know most people think of Hive in terms of rewards, but it is also a free to use database that is hard to take offline. Some people are exploiting that aspect of it.