Find out exactly what he used , but honestly he could have just thinned
it out, whatever it was, screwing you and the varnish performance.
The real point is a quality job will not be affected by water drips,
if yours is he screwed you, how or why is not realy important . But the
fact that it needs to be re-done, or re-coated is. Take photos and get 4
or more bids in writing from real pros as to the problem and long term
cure. Quality painters, cabinet and wood finishers are a start. And get
the manufacturers name of the product he used and call the company. My
boat oars, and exterior doors are varnished, boats and wood get
varnished and can last many years, My doors will last 30+ in the shade,
thay have lasted 10 so far and look new. If your kitchen was done right
this would not be an issue for 10-30 yrs. Yes I have refinished alot of
wood professionaly for many years.