разочаровывающий

adj.

all sizzle and no steak (о событии или человеке Fyrvaktare)

dusty; not all it's cracked up to be (SirReal)

disappointing (oleg.vigodsky)

disappoint (to fail to fulfil the hopes or expectations of • London disappointed her after all she had heard about it); disenchant; disillusion (to destroy the false but pleasant beliefs (held by a person) • I hate to disillusion you, but your boss isn't the perfect person you think she is); let down (to disappoint or fail to help when necessary etc.); chagrin; sophisticate; balk; disillusionize; disaffect (someone bigmaxus); underwhelm (MichaelBurov); chill; deflate; burst one's bubble (КГА); bum out (To sadden one or cause one to feel disappointed. In this usage, a noun or pronoun can be used between "bum" and "out." • I can't watch the news because it always bums me out vogeler); disabuse; uncharm; undeceive; unspell; be a bit of a downer (Anglophile); have; had; turn off; let the side down

let the side down (окружающих своим поведением; to behave badly or do something that embarrasses or disappoints your family, friends etc Sonora)

rain on someone's parade (VLZ_58)

deceive (преим.)