L'Espace 180 - I thnk a lot of people call certain liveries "boring" because they lack imagination, originality and colour. Air France was the first to introduce the "white body fuselage" look. That was original and imaginative at the time. It was also more than 25 years ago in the 1970s. Today many airlines, too many airlines, have their version of it (Garuda, Lufthansa, Air Canada, British Airways, South African, Air Afrique, Ansett, Air New Zealand, Swissair etc) thereby becoming repetative, common place and unoriginal. Their logos and tails may be excellent (SA, AC, AF, GA) but it may not be enough to carry the look in it's entirety.
Other carriers have come up with dynamic new unique looking liveries (Northwest, Lan Chile), beautiful retro looks (American's Astrojet, Air Canada's "Trans Canada" 60th anniversary livery), speciality paint jobs (Air Canada's Raptor livery, Hawaiian's "lady", Bangkok Air's Tropical colours, SIA's Tropical Winds), classic schemes that hold their own over time (American, Air india, Ethiopian, KLM) or just plain new and original images (Virgin Atlantic, China Airlines). These are less "boring" because we see them repeated less often, are sometimes more colourful and innovative and are unique in their own way.
All that being said it still helps to update them once in a while so they don't become tired. Air France, American, Iberia, Alitalia, Olympic & KLM have been flying the same image for decades. It's interesting to see people attack Iberia & Alitalia for being old and tired looking while defending American as being a classic. It may have more to do with one's nationality but also how we perceived the image. A good paint job goes a long way for a carrier in gaining respect and global attention.