To be fair, dog-Spike was great. He had some terrific lines as I recall, and being made a dog didn't make him any less of a character than he usually was.
In general, Spike strikes me as a low-priority feature from both a writing and a marketing perspective. He absolutely can be an interesting character, but the show is called "My Little Pony", and I can't imagine anyone at Hasbro or DHX are oblivious to that.
To respond to the top part, I am related to some children who didn't really appreciate that.
To the bottom.
Way to miss a toy opportunity,
Hasbro guy : what thing in this show can we use to launch and entire other line of toys. Maybe something more middle of the road when it comes to the whole gender/toys debacle. Something that has an entire other section of this world un-explored, and we could use a character we alread have to easily enter this world and sell these toys... If only we had something like that. Something that children adored all around the world, and people in general
*Someone Feverishly points to spike and dragons *
Hasbro guy: Nope can't think of nothing , screw it. We going after the monster high market , making a movie.