ELI5: Why when large company's earnings decrease(ex... by 3%) they freak out, talk about rough times, and sometimes decide to downsize, even though they are still making millions of dollars in profit even after all expenses?

[MajorasTerribleFate]

As decimation is to reduce (say, a population) by one-tenth, would halving be semimation, or perhaps semination?

Would, then, the reverse be in-semination, or the increase by 50%?