The most important part of Diesel is that it's free. It's hard to beat a free 3 cards, using only 1 card and a click. Essentially, it turns a two-click double-draw into a one-click double draw. It's difficult to imagine a scenario in which this is bad. Perhaps it makes it harder to decide whether to mulligan. On the other hand, it helps draw out of a bad or mediocre hand (or make a good hand better.) If you plan on ever drawing cards, Diesel is fantastic. It even serves to thin your deck.

In Shaper decks, it's pretty much an auto-include. In Anarch or Criminal decks, it may be worth it depending on how you need to spend your influence. Otherwise, pretty much every deck should run this.

Some might compare this to Anonymous Tip. However, drawing cards as a corp is different than drawing cards as a runner. As a corp, it's dangerous, since you're increasing the number of agendas available for the runner to access. You're even getting closer to drawing out your deck. With a forced draw each turn, often you would rather not draw another card. A runner has no such limitations.

Others might compare it to Ancestral Recall from Magic: The Gathering. In Magic, it costs 1 mana, in Netrunner it costs 1 click. Ancestral Recall is considered one of the top 9 most powerful cards in the game, if that gives you an idea of how strong it is. Netrunner may be a different game, and clicks are definitely not mana, but free cards are free cards.

Very niche, at best. Usually horrible.

The main reason you would want to use this is to prevent being blown out after having taken tags, etc. Triple Scorched Earth for example. Unfortunately, if they're capable of doing that, they'll just take the bad publicity, which makes it rather useless as protection.

Alternatively, you might be seeking to give them bad publicity. Unfortunately, they can just choose not to damage you until their next turn. How much will that really save you?

So then you might be thinking... perhaps if I forced them to make a choice before I make a move, I could either run without risking taking damage, or get a free 2 bad publicity out of it. Unfortunately, it also requires you to have already made a successful run on HQ the same turn. So it's only useful when making a run on HQ is easy, but you are afraid of trying something else. You're relying on HQ being an easy target. And all for (at best) 2 bad publicity.