Your irritation must be founded on something other than grammar. The two sentences have slightly different meanings.
I love X.
expresses the action implied by the verb 'love' (from 'to love'), and applied on the predicate X. The second sentence
I am a lover of X.
expresses membership to a category. The membership is expressed by the verb 'am' (from 'to be'). The name of the category is 'lover of X' in which 'lover' is a noun.
One could deduce that if 'I am a lover of X' is asserted then it likely follows that 'I love X.', 'I love X now.', or 'I loved X.' are also true. On the other hand, it is possible that both 'I am a lover of X' and 'I am not loving X this time' are true simultaneously. Perhaps that could be irritating if one asked me if I love X and I reply with 'I am a lover of X'. The person inquiring might not be certain from my answer if I am asserting loving this X right now.