Agreed 100%. I had all the mats to level 1-400 on my alt. Logged in after the patch and only got 7 levels. Was pretty annoyed to say the least. Seems unfair that anyone who leveled before got 10 levels out of it + the bonus levels from 400-500, and anyone after is punished.
I always just assumed that if new levels were being added, it would be in addition to existing XP, to minimize the negative effect on anyone not interested in the ascended weapons (such as myself).
And I’d like to point out that there are people who don’t level 1-80 using crafting, but DO use it to supplement alt leveling, as has always been intended by Anet. On all my alts I max out 2 professions to give me a break from leveling. This now gives my alts 14 levels, compared to the 20 it used to. This is quite a large difference.
TL;DR The new change sucks. Put it back the way it should be to avoid a split where half of players gain more of an advantage from the patch than others.