No, he's suggesting that MPs should be able to conduct business in secret because portions of the public have concerns that they have good reason to raise with an MP yet where even the mere knowledge of the basics of the conversation might negatively affect their lives.

E.g. lets say a drug addict who has successfully managed hid their addiction wants to offer their perspective of new drug legislation to their MP. Or a paedophile who wants to gather support for promising treatment option. Or someone with family or community ties to extremists of some shade or the other wants to propose ways of reducing their influence.

There are a multitude of situations where there might be bad fallout from public knowledge about what a persons raises with their MP even if what they raised is positive for the wider community.

Yes, secrecy also allows for negative effects, but it's not nearly as simple as just writing off the benefits of being able to guarantee privacy.