Limits and otherwise
Look, this is all much simpler than is being argued.
The design approval of an aeroplane requires certain facts to be established. Hopefully someone will find the actual design regulations and link them here, it has been found before but some time ago.
The Demonstrated Crosswind Component is not an actual flown exercise but a mathmatical calculation based on designed control available. It is generally understood that this calculation demonstrates that an average pilot in reasonable practice should be able to control the aircraft safely when landing. The italics are not the regulation but how they might reasonably be interpreted. However these calculations are only one part of a scenario where many other factors may be dominent such as pilot ability and other considerations pertaining at the time. This is usually the case with light aircaft and therefore it would be impossible to define a limit. I'm sure that there are light aircraft with a crosswind defined limit, just the same.
A limit is normally applied to larger heavy aircraft (although not only) when beyond such a limit, control of the aircraft is unlikely irrespective of the pilots ability. This could be say a limit on the maximum angle of bank during landing owing to the fact that the wing tip, engine nacelle or propellor could strike the ground. There will be various reasons but i'm sure it is obvious that with the above restrictions the pilots choices are 'limited' and so therefore is the maximum crosswind.