I have accumulated enough passwords that when I unlock the vault I have to go searching through a lengthy list for the item I want. Takes a few seconds. Often I use the search field. It would save time--and also save the extra step of having to click in the search field--if the cursor was located in the search field by default when the vault is first opened.
I can't see how that would slow anyone down. If someone didn't want to search, but rather to select a folder, for example, they'd have to click somewhere anyway, regardless of where the cursor is located by default.