This is a common misconception and source of fear/uncertainty/doubt regarding copyleft licenses. It's true that, the stronger the copyleft license, the more obligations it imposes on companies, and the AGPL is perhaps the most onerous of all and thus the least attractive to businesses. But, copyleft exists on a spectrum, and there are thousands of big-ticket FOSS projects that tens of thousands of businesses depend on and make use of that have a copyleft license. Linux itself is GPL, and pretty much everyone depends on it.

The license for Redict is one of the weaker copyleft licenses and should not pose any onerous compliance obligations on the most common commercial use-cases for Redict.