Well, if that is the attitude to take, why have a minimum connection time at all? Why not just let people do what they want? Give someone, who has no knowledge of the change station, the free choice of a connection time and they will usually pick one that gives them the best journey time, rather than one they can actually make, so the problem with letting passengers choose the connection time is, frankly, the passenger (no offence intended).
I see nothing wrong with having a 'minimum' and 'recommended' minimum connection time, especially if journey planners could take into account the platform trains are scheduled to use. If a passenger misses the 'minimum' connection time yet there is no disruption, he or she is not entitled to claim compensation for delay. Simple.
Crewe, for example, has a ridiculous minimum connection time of 10 minutes, prohibiting all of the following very reasonable connections for Nantwich travellers...
Nantwich [08:15] to Crewe [08:24] (arrives platform 6)
Crewe [08:29] to London [10:04] (departs platform 5, across the footbridge)
yet one has to wait for Crewe [08:56] to London [10:38] (departs platform 6)
Nantwich [07:13] to Crewe [07:24] (arrives platform 5)
Crewe [07:32] to Glasgow [10:36] (departs platform 6, across the footbridge)
yet one has to wait for Crewe [08:09] to Glasgow [11:17] (departs platform 11)
Nantwich [15:18] to Crewe [15:27] (arrives platform 6)
Crewe [15:32] to Liverpool [16:10] (departs platform 11, opposite)
yet one has to wait for Crewe [15:57] to Liverpool [16:45] (departs platform 11)
I could go on and on. These minimum connections times are really annoying for the regular traveller (which probably constitutes the majority of travellers making journeys involving connections, at least on weekdays), the Kings Cross to St Pancras minimum connection time being no exception.