Well, it seems that this controversy is all down to a difference in what the meaning & understanding of "clear to land" actually is in two different ATC cultures.
In the UK, the phrase means that the a/c is physically CLEAR to land. That is, NO obstacles to the a/c doing so. In the US, it simply means that the a/c MIGHT be clear to land - all things being equal at the time that the actual landing is to take place !
However, I believe that the US practice leaves a lot to be desired, particularly in a "legal" i.e. The Law, situation following an incident occurring as a result of the confusion which this procedure so obviously leaves itself open to. In this regard, I think that the US ATC authority & its ATCOS are exposing themselves to possible litigation & criminal legal cases.
Be that as it may, if "clear to land" is used as a perfunctory response to a mundane situation (eg. A sequence of a/c approaching to land), & has actually no relevance to a safe landing scenario & clearance, WHAT is the practical use of employing the term ?
Surely,& bearing in mind that ATC can alter this "clearance", should the need later arise, it would be better to employ a different "perfunctory" response to the landing sequence in the first place. Therein preserving the "sanctity" of "clear to land".