I use statistics to -limit- my characters, not to win an e-peen competition. The fact is if you write vague abilities in your CS it isn't suitable for ranked play, because the honour code does not exist. When everything is on the line and you're fighting in a competitive sense the majority of fighters will use everything to their advantage, and vague abilities are the cornerstone of bullshitting your way out of a tough situation. Statistics enforce some degree of control over the parameters of a fight, with strict limits come inventive strategies and play that forces you to actually think.

Case in point, look how much trouble was caused by Divinity's vague skillset in their ranked fight with Dazsos, that would not have happened if everything was quantified properly. Now they have to argue over every action because no proper limitations were set going into the fight, and so there are no regulations. Neither wants to lose, so both are pulling out spell after spell to counter each others every move and there is no good way to fix the situation any more. 

tl;dr Statistics are a limiting factor which is what makes them useful, generally vague descriptions of abilities are going to leave too much room for subjectivity and cause problems in ranked fights.