Waste and extravagance, poor ethics, sloppiness and inefficiency in intellectual or artistic works can be very disappointing to you.

铺张浪费、道德意识薄弱、松散懈怠的、艺术感和智能低下会让你感到非常失望。

youdao

The play was built up to be a masterpiece but I found it very disappointing.

那部戏被捧为杰作，可我却大失所望。

《牛津词典》

It's an American way of talking that questions should be answered before being explained, even if answers might be something negative and very disappointing.

美国人的谈话方式是先回答问题再解释原因，即便答案有可能是否定的，并且很令人失望。

youdao

"It would be very disappointing for me not to play, " Ferrer said.

BBC: Ferrer agonises over Euro 2000 chances

Mr. LEACHMAN: It's going to be very disappointing if this administration emphasizes a need for the energy here but turns its head to the importance of one of the rarest mammals in North America.

NPR: Drilling to Begin in Colorado Ferret Habitat

But a loss of 1, 400 seats would imply a lead over the Tories in terms of a national equivalent vote share of only some 4%, which would be very disappointing compared with Labour's 31% national opinion-poll lead.

ECONOMIST: How to see through the spin