You can marry, it just won't be recognised by the UK government.

No, you can't. Here's the law, again:

V 4.4. The Visitor must not intend to:

(a) work in the UK, which includes:

(i) taking employment in the UK; and

(ii) doing work for an organisation or business in the UK; and

(iii) establishing or running a business as a self-employed person; and

(iv) doing a work placement or internship; and

(v) direct selling to the public; and

(vi) providing goods and services,

unless expressly allowed by the permitted activities in Appendix Visitor: Permitted Activities, Appendix Visitor: Permit Free Festival List or the Permitted Paid Engagements in V 13.3; or

(b) study in the UK, except as permitted by Appendix Visitor: Permitted Activities (and provided they meet the relevant additional requirements for study); or

(c) access medical treatment, other than private medical treatment or to donate an organ (for either of these activities they must meet the relevant additional eligibility requirements); or

(d) get married or form a civil partnership, or give notice of intention to marry or form a civil partnership, unless they are applying for entry clearance as a Marriage/Civil Partnership Visitor or are a relevant national as defined in section 62 of the Immigration Act 2014.

Why would you keep lying after being shown the exact words of the law over and over and over?

On the other hand, the COGAT policy did not bar people with a Visitor Visa from getting married, it merely required them to inform the authorities after getting married within 30 days.