Well I would agree with you, but if you look at the legislation and then refer to the following paragraph (see below) then it suggests that if the land is within the curtilage (which includes the grounds of a hotel) then the 28 rule does NOT apply.
Class B – temporary use of land
Permitted development
B. The use of any land for any purpose for not more than 28 days in total in any calendar year, of which not more than 14 days in total may be for the purposes of—
(a)the holding of a market;
(b)motor car and motorcycle racing including trials of speed, and practising for these activities,
and the provision on the land of any moveable structure for the purposes of the permitted use.
Development not permitted
B.1 Development is not permitted by Class B if—
(a)it would consist of development of a kind described in Class E of this Part (temporary use of land for film-making);
(b)the land in question is a building or is within the curtilage of a building;
(c)the use of the land is for a caravan site;
(d)the land is, or is within, a site of special scientific interest and the use of the land is for—
(i)motor car and motorcycle racing including trials of speed or other motor sports, and practising for these activities;
(ii)clay pigeon shooting; or
(iii)any war game, or
(e)the use of the land is for the display of an advertisement.