It really is not about the 'taste'.
Garden hoses have lead and chemicals in them. Have for years.
Ya, we all drank out of the garden hose one time or another when we played outside.
BUT we were not drinking out of it all day and night for days at a time as in an RV. If you have kids on board the RV the lead issue is real BIG issue because it affects there brains just like lead paint does.
The so-called white safe hose for RV's has been found to have traces of lead in it also. Much of it coming from the fittings. So it can state 'lead free', but that just means the hose not the fittings. The RV white hose has been shown to have lead in it from the fittings.
Here is but one of hundreds of information sites about lead in garden hoses.
http://saferchemicals.org/newsroom/new-study-rates-best-and-worst-garden-hoses/One thing I will pass on from experience is if you are RV'ing in the south. Green 'mold', not algae, but real green 'mold' builds up inside the hose over time. When it lays outside on the ground in the hot southern heat.
One of the best ways to prevent build up of the chems and mold is to NOT store the water hose without completely draining it each time before you store it. And do NOT connect the two ends together.
Once I found that green mold inside mine, I started putting a 1/4 cup of bleach down the hose and then some water before storing and bought a new hose every other month.
RV'ing in Florida does have it's challenges. :(