FUD:

“Knots is only maintained by one dev.”

Answer:

1) The majority of Knots code is the same as Core, core devs are effectively contributing to knots also. There isn't much of a difference for the essential cryptography functions, same implementation and security as Bitcoin Core.

2) Game Theory - there's no shortage of Luke/Ocean/Knots haters. If there is a problem with it, why hasn't it been exploited yet? You know there are people financially incentivized to take it down.

Suppose there is some ciritical vulnerability in Knots that slipped by the review process. Why wouldn't it already be exploited?

Knots is a high-value piece of software to exploit, surely there are people that would be motivated for political, social, or economic reasons to hack Knots. Knots comprises 13.5% of the bitcoin network, and is relied upon by miners and institutions with high value holdings.

If this theoretical vulnerability exists, why hasn't it been exploited yet? Occam's Razor suggests that no such vulnerability exists.