Foreign born mlb players in 1960 = 63
Foreign born mlb players in 1980 = 112
Foreign born mlb players in 2018 = 432

There is no evidence the game is diluted, rather there is evidence that there is more competition than ever to make it to the major leagues.

Let's check your contention that pitchers have no command.
Average walk rate in 1960 = 3.39 per 100 plate appearances
Average walk rate in 1980 = 3.13 per 100
Average walk rate in 2018 = 3.23 per 100

All this while average fastball speeds are at all time highs.