It is, in part thanks to more aggressive anti-poaching practices in the region. Remember, everyone: if you must obtain a bulbasaur from a person, be sure to do so only from a certified breeder, shelter, or pokémon professor.
That having been said, I quite agree with you on the subject of bulbasaur, but perhaps I’m a little biased. Other than eevee, I maintain that bulbasaur is the best starter, and anyone who disagrees would be welcome to meet the fully evolved starter with the best disposition I’ve ever met.
Bill, your venusaur is that well-behaved because it’s unconscious for half the day and eating for the other half. —LH
Resting, Lanette. He’s just resting. It’s not easy being a guard pokémon. —Bill
Considering you live in a remote corner of Kanto? I’m sure it isn’t. —LH
The Pokédex According to Bill 