That still doesn't make sense in the original context ("it always seems [unfortunate for me] that someone likes both YA and urban fantasy"), but I'll take it at face value...
In all honesty, reading one [insert genre here] book does not qualify someone to judge the entire genre - no matter what that book or genre is. Suppose someone said that they know they hate disaster movies because they saw
Sharknado and didn't care for it. Would you consider recommending
The Poseidon Adventure or
Airport as other examples of the genre, or just write them off?
Remember that
Sturgeon's Revelation applies to all genres, not just SF and not only in written form. There's a lot of crud out there, and the boom in UF and YA means that there's a lot of it in those genres...but the flip side of that is that there's also a decent amount of good stuff to be found.
Now, it may well be that a certain genre is not to your taste because of something inherent to the genre. I have no interest in Regency romances, none at all. I prefer my romantic storyline to be the B-plot (or lower), not the A-plot, and I have no interest in that setting, so no matter how well-written an RR book may be, I'll pass. Contrariwise, I like the contrast of a modern-day setting with magical elements, so I'll forgive some flaws when reading UF. Sometimes I'll even "cross the aisle" into paranormal romance, if there's something particularly compelling about a book. (Or, rarely, a series. Dakota Cassidy insists that her "Accidental" books are PR, where I enjoy them as comic UF that happens to have a romance A-plot. The romance A-plot would normally take 'em off my list, but the concept and comedy outweigh that "flaw" for me.)
All I'm saying is, since (part of?) your objection seems to be rooted in the level of the writing, don't miss out on a whole genre based on a single-book sample. Yes, I do happen to read and enjoy Patricia Briggs's "Mercy Thompson" books, but I also love Jim Butcher's "Dresden Files" series. For that matter, I like Ilona Andrews's "Kate Daniels" series but don't really care for their* "The Edge" series - and they're both UF. I loved Kelley Armstrong's "Otherworld" books but couldn't stand the YA UF trilogy she wrote.
Tastes vary. Make sure you give yourself a fair shot.
* Ilona Andrews is a single name for a husband/wife writing team, hence "their" instead of "her."