You raise an interesting question. I think sometimes the gesture is important — even whether or not the note was prefilled and I didn’t change it. I did mean to reach out to you and say hi and hear more about what you were doing. I thought it was great that LinkedIn triggered this and I’m not sure if it had been empty if I would have said something much different.
In situations like this I’ve found that as long as the user explicitly has to take an action to send the message and confirms the words (vs if I had hit “like” and then that message got sent), it’s still a good sign of communication between two people.
Where i tend to see this fall flat is when you respond with a personal message and the person who sent you the “defaulted” message doesn’t respond again. In that case, it’s no better than a like and you should be annoyed at the person. But in our case I was glad to engage and learn that you weren’t actually going anywhere too :)