Having high hopes usually leads to disappointment.
Manny Machado's .782 OPS represented a major letdown last season, but Baltimore Orioles teammate Tim Beckham enjoyed a breakout campaign by registering an identical rate. Results are constantly weighed alongside expectations, so too much hype can give good outcomes a mediocre stench.
Before firing off angry tweets, remember that this is not a list of 2018 duds. Expectations have simply grown a tad out of hand.
Youth, instant success, a big market and/or a sizable payday made these guys susceptible to a hype overdose. Things especially get out of hand when a young star shines immediately on a big-market team.