Cockers:
(in no particular order)
1. there (former)
popularity and current reputation
Popularity brings BYBs, Mills, genetic / health, and temperment/behavior problems.
Somehow they've gained a reputation for being yappy, snappy, bad with kids, etc
Quite frankly, the Cocker Spaniel is not for everyone. From 1936 through 1952, and again from 1983 through 1990, it was the #1 breed in the USA according to AKC registration statistics. But a lot of people had bad experiences with Cockers, and it's no longer even close to being in the top 10 anymore. (which is fine with me!)
2.
Eyes, Ears, and Allergies
Cherry eyes, Glaucoma, cataracts, Ear infections, Seborrheic dermatitis and about a million other possible skin problems...
3.
Excited urination or submissive urination
Compared to other breeds, Cockers are more likely to lose bladder control when happy or frightened. Of course, most Cockers do not do this, but some do... and it can be a VERY frustrating problem to live with. Or so I hear
4.
Coat and Grooming
5. Many Cockers
don't handle being alone very well
because they are so people-oriented
They may bark, chew everything in sight, dig in your garden, or pee & poop destructively. When you finally get home, a crazed monster is waiting for you. If you've heard that Cockers have a reputation for being hyper or a little crazy, it's because of all the people that have thought they could just leave a Cocker alone until they got home.
IMO
GSDs
1. Shedding
2. Reputation
3. Shedding
4. Exercise
5. Training
6. Shedding
7. Some have high Drive, or dominence, whatever you may call it.
did I mention shedding? According to my local GSD rescue, a lot of people get rid of their GSDs because they get sick of the hair, or they can't handle the distructivness...