PC Matic as well as the rest of PC Pitstop software are considered to be a PUP software.
Ummm, first and FTR, "potentially" unwanted is totally different from dangerous or malicious. And it is highly opinionated. I personally have had more than one "wanted" and "safe" program tagged as a PUP.
While Malwarebyte's stated intent may be to warn users of a developer's aggressive actions to foist changes on our systems without warning, or with misleading fear tactics, or without the ability to opt out of said changes, MB has, at time, been overzealous causing users to become fearful of perfectly safe programs unnecessarily. If not paying attention to what MB is doing, it will block and/or quarantine a wanted and safe program.
So while I love, have and use Malwarebytes on all my systems, I do not trust it to tell me what is wanted or unwanted, potentially or otherwise.
Second, it you scroll down to the bottom of your link, it says,
UPDATE:
We are excited to announce that Malwarebytes is no longer detecting PC Pitstop’s product, PC Matic, as potentially unwanted software. PC Pitstop has not only stopped using scare tactics against potential customers, they have gone as far as removing registry cleaning from their product by default.
Having noted that, I personally would not use PC Matic. I use Microsoft Defender (formally Windows Defender) along with Malwarebytes on all my systems, have for years, and never had a problems with malware, or performance issues.