a foolish consistency is the hobgoblin of little minds
go nowhere
mobility
if it ain't broke, don't fix it
counterproductive
nonadaptation
let the grass grow under one's feet
qualitative leap
nonimprovement
flat out
rigid
imperfectibility
inflexible
unbending
nonadjustment
inconsistent
little strokes fell great oaks
misfire
law of diminishing returns
sophomore slump
high-hanging fruit
inadaptation
creeping normality
rough edges
incompatibility
gimmick
go over like a lead balloon
checkered
insecure
failure
apologize
clash
die on the vine
leave a lot to be desired
catch
be careful what you wish for
unlikely
flow-on effect
uptick
apologise
irreversibility
nonfailure
nonadvancement
zoom
self-defeating
strike out looking
lability
unprogress
nonconform
miss the mark
misoptimize
unimprovement
flaw
downtick
adaptate
velleitary
nonprogress
chaotic
inexact
push one's luck
fossilization
unadjustment
progresslessness
uncontriving
mismeet
overchange
unadaptability
underachieve
unready
fluctuance
uncommercial
underperform
disadaptation
unsettled
unsuccess
tough cookies
unresolve
plateau effect
tough titty
tough toodles
tough tuchus
conflict
scrape the bottom of the barrel
nonfixation
static
weakness
scratchy
imperfection
failing
uneven
pseudoimprovement
spotty
lameness
erratic
dripping water hollows a stone
more is more
noncontinuity