With Kara getting her body destroyed, you would think Kal would have flown over to help her out, right?
Or Mon El and Jonn would have leaped into battle?
Wouldn't that make Kara look bad though?
Worse than she already was looking? Nope. She's been helped tons of times in the past, and it was cool. It doesn't necessarily have to "bail her out," so much as just provide enough support that she can get the job done.
You might have a point if the show seemed at all interested in presenting a truly super Supergirl, but they never have. Episode 7 had her burn out after fighting Red Tornado and breaking her arm. 2 seasons later, she's not significantly more powerful.
If they're even going to bother with having her support system, use them. It's kind of like Chekhov's gun, by now.
And they're not limited to the guys. If they want, use girls. Alex was awesome in the suit she used to fight Metallo. Imra's right there too.
They had many persons able to help her, like the ones you mentioned, and having Superman show up, isn't that what he does period when a world class threat appears?
If DD attacked Kara city, would we expect him to watch it live on the TV only?