I dont think leif really needs his own shop as once you have your bushes placed, they're placed.Does anyone find it weird how when you first played this game that the very first special villager that showed up on your island was Mabel? It used to be where she would come on some days when you buy clothes from her and after enough shopping with her, she becomes interested in setting up a shop. When I first played this game I thought Kicks and Leif would get the same treatment. After over a year it doesn't seem like they got their own shops.
I mean I don't really care for Kicks because he sells only shoes, but with Leif I really had to wait a week or sometimes longer for him to show up whenever I want to buy bushes from him. After a year I just just wished Leif had his own shop by now.
The only reason I buy from him at all now is because every couple months you need to dig up every bush and replace them with the ones in season.
I think he would need more to do than just being a bush vendor to justify a shop.
But I certainly would agree that its annoying when you want new bushes and have to wait for him to show up.
I've taken to buying the next seasons bushes in advance and keeping them in storage to get around it.