Is the verb "hustle" used mostly positively or negatively these days?

Solution 1:

"hustle" can certainly connote "trying very hard", "giving your best", and "not being discouraged by failure", depending on the context, but its definitions in such regard are:

to obtain by energetic activity

to make strenuous efforts to obtain

So hustling in this sense is just a focused action toward achieving something beneficial and doesn't in itself denote the positive qualities that you mention.

Solution 2:

To hustle or hustling is used in two very different ways.

1. Action a person who is conning another person out of money (or something) is taking.

2. The meaning that someone is trying hard or doing something quickly.

Uses:

1. That guy is trying to hustle you. Don't play his little game.

2. John is really hustling today. The rest of you need to step up your game.

So when used in the first meaning it is negative (maybe even super negative). And when used the second way it is positive to be hustling.

Solution 3:

The dictionary does contain positive, and only slightly pejorative, definitions:

(1) To make someone go quickly where you want them to go or to make them do what you want them to do.

(3) [US] To move in a quick, effective way.

(Oh, this is Macmillan, though. The other dictionary.)