Its a good trade ratio under the assumption it's successful, but there's the question of how likely is it to succeed.
Another example of a dive might be diving a USF base with a panzer 4 to snipe the ambo. You are potentially trading 120 fuel for 10 fuel, but the risk associated is much lower because the panzer 4 only needs to get one shot off, is far more durable then the kubel and that you know exactly where the ambo is at basically all times.
Even if it forces the sniper to retreat, you win. In either way getting a kubel is a clear victory over the sniper. It will force a retreat at the very least and with a bit (rank 1-1000 skill) of skill, it kills. Kubel can cap, is fast, can easily harass max range troops out of cover and bleed manpower. It fulfills multiple roles easily. It's especially good with 2x sturmpios opening on most maps in teamgames. Can't tell how many times I've fussed about a rogue kubel harassing rifles and giving sturmpios a chance to get up close and personal.
Kubel forcing a retreat from sniper is a clear win in any textbook