The basic gist of the thinking of 3 MLB players interviewed seems to be that there are two reasons they don’t just hit to the left (sparsely fielded) side of the infield.
[li]Hitting a double (or HR) is a lot better than hitting a single.[/li][li]There’s no guarantee that they’d get a single either.[/li][/ol]
The first of these seems completely ridiculous. The likelihood of even the top players getting an extra base hit in a given AB is not more than about 15%. If they could have even a 60% chance of getting a single by hitting to the left side, that would be much better than a 15% chance of an extra base hit (plus a reduced chance of a single against the shift). And further, if they did get their batting averages up by getting 60% singles through the left side, then the opposing teams would abandon the shift, which would then allow these hitters to be even more successful hitting straightaway.
ISTM that these interviews reveal players thinking irrationally. They’re ideally trying to get extra base hits, so they’re focused on extra base hits at the expense of what would actually help their teams. So they’re viewing things too much in terms of “what would help me hit a double?” versus “what actually advances the teams chances?”