this also turned me off. It's backed by a for-profit company which can be sold/acquired anytime. If we have learned anything from DigiNotar, Startcom, etc? Trust is a dangerous commodity to have changing hands.
Anyway scrolling down to the bottom¹ they seem to be resellers for DigiCert/Symantec certificates. So based on their strategy to fish for users with free certificates, I'd strongly question both their motives and their track record with handling the technical requirements for operating a CA. If they are a serious actor in this space then they should at the very least have either ETSI TSP² or WebTrust³ certifications to meet the security/trust requirements for operating a CA. Judging from the info on this site, I doubt they do.
¹ https://www.certcenter.com/company/terms
² https://portal.etsi.org/tbsitemap/esi/trustserviceproviders....