Properly formed crimps will not fail due to corrosion. If a crimp is properly made, the stands of wire basically cold weld together. No air or liquid can get in to corrode the joint. If you just use a pair of hinged plier type crimpers, you're bound to be making improper crimps. You need a good quality set of crimping pliers that crimp to a set dimension, to use the correct size die, and the terminals need to be properly sized for the wire used. Miss on any of these and you get garbage crimps.
If that's the case, yes, a solder joint will definitely be better. However a properly crimped joint is better yet for any environment with a lot of vibration (tractors, cars, space ships, etc.) due to solder joints being so stiff. Soldered wire joints will often fail at the transition between the soldered and unsoldered wire, especially if there's any movement in the wire. The crimp terminals allow the wire strands to flex and move better.
I do frequently add a bit of adhesive lined heat shrink over my crimped terminals also though, better safe than sorry, and it also adds a little more strain relief and environmental protection, especially in areas where things can get wet and if there are no weather sealed fittings.
