Have to say I agree 100% with Jane and Pammy. If any dog, let alone a puppy, is left alone all day (in or out of a crate), with just a break at lunchtime, then it's extremely unfair, imo. My OH and I are very fortunate in that Milo comes to work with me and isn't left alone for long periods. Between us, my OH and I took time off work for the first few weeks he was home and then he started coming to work with me. It took careful planning and consideration, we didn't have a proper holiday last year and spent most of our days off apart so there was always one of us at home with Milo while the other was at work. Because of the time and attention we gave to Milo, he was toilet trained within a week. I know we're very fortunate to be in the situation we're in, but if I couldn't take Milo to work with me, we would have reconsidered having a dog until our circumstances were different and we would have a dog sitter or friend come in at least once, maybe twice a day. Alternatively, we may have rescued an adult dog who was already house-trained and didn't need letting out as much during the day to relieve themselves.
Edited to say, just re-read this post and realise it comes on a bit strong!
Don't mean to offend anyone and know that not everyone is as fortunate as us.
However, I do feel that people who are at work all day and are unable to devote as much time to their dog's exercise, stimulation and training needs, can only expect their dogs to take longer to get the hang of things.