Heh, depends on what you define as the "normal way", because bobby pins are not it (at least not for doors leading outside a house or appartment)... Then again, all locks since Fallout 3 are Wafer locks, and they don't look like the secure versions... so meh, talking more about UNsecurity ^^. Anyhow, a full manual professional set would have no big problem with any conventional lock (aka opened with a normal turning key, no matter if the keyblade has 1 or 4 sides, that would only take longer and be a more fiddly job, as long as one does have any putty for a partial print ^^")
Edit: Btw, a Cross or Zeiss Lock is even easier to pick, it's just a normal tumbler with up to four sides. Nothing at all like a REAL Zeiss-Ikon Secure Lock, which could literally take HOURS to SPP xP
For reference:
https://lock-lab.com/locklab-university/types-of-locks/
Also, since the player character only seems to know how to "noob rake", he would of course not be able to open every lock. Well, realistically not even 5% of the locks ingame, since he has only one type of "rake" (I really despise calling a bobby pin that ^^"), but oh well.
So yes, it makes kind of sense ingame to need keys, but then it makes no sense how many pre-war locks still work and could be easily be raked with a bobby pin... *shrug*