** my opinion on this situation **
in my opinion (granted i've only been on the forum since it was first taking off 5 years ago) giving people rep for whatever reason is less harmful to the forum than something similar like abusing the like system.
with the like system you can gain meaningful perks such as vouch copies and hidden content bypass whereas with reps it's just a number, you gain almost 0 real perks from it.
you can give rep for any reason - and it's very common to rep people for helping with anything (onsite or otherwise) or just being generally a good person.
giving rep to someone for helping you reach a goal of yours as i see it is a very valid reason.