Again, you play where you have a good chance of winning and you play early. Tougher seats don't become competitive until much later in the cycle and that will be the time to play in those seats.
Yeah, that's been the conventional wisdom for the past few cycles.
What's happened though is that this monomaniacal focus on swing districts has actually lead to a slow retreat of the viable universe for Democrats.
If you're not funding congressional candidates in a district that you currently consider out of reach (along with the DLCC likely not providing funding/recruitment for downticket candidates in the area) you're vitiating your bench in that area, hurting your statewide vote totals, and local Dems feel demoralized, independents and swing-Republicans in the area feel (quite rightly) that the Party doesn't really care about the area. Pretty soon, if that area wasn't out of reach for a good candidate before, a good candidate for the area that comes along by chance won't have the infrastructure, enthusiasm, or perceived viability necessary to actually contest it.
Targeting swing districts and only swing districts make sense if you're looking only at Congress, and only in one cycle. But if we want to win statewide races in swing states, keep the party alive in red states, and force GOP Presidential campaigns to at least pay token attention to their safe states, giving every congressional district at least a modicum of support every cycle is incredibly necessary.
Should the DCCC be carpet bombing the IN-9 with ads? No. Should they have given Shelli Yoder the tools she needed to succeed, and a little bit of money (or ideally, have recruited a better candidate than Yoder?) Absolutely, and to suggest that instead the DCCC ought to double down on the trendy nonsense of targeting moderate suburban districts to the exclusion of everything else is just plain wrong.
