With all due respect, that's only partially accurate, and depending on the player, that small portion of a difference can be a minor or major difference. It's physics, and you can't circumvent it. There are two variables at play in determining the pitch of a note. Mass (of the string) and tension. Changing any single variable in those two causes the pitch to change if the other stays constant. Increasing the length allows you to obtain the same pitch (a low B) with more mass (since more string is present) AND greater tension, and you can do it with a smaller diameter string (if you prefer) since the mass is added in the length of the string. Or you can also use a larger diameter string to get even more mass so you can also raise the tension. Your statement is only 2/3 of the story. Length is the other 1/3 that determines how much tension you'll need with a given mass. So while the pitch is based on mass and tension, length is used to allow you to manipulate those other two.
But pitch of the note is only part of what we hear. Harmonic overtones, "punch", and clarity are what tend to increase as you add length, even if mass and tension stay the same (meaning you are using a progressivly smaller string). Of course, if you use the same diameter string and add length, then the tension goes up, allowing the string to ring even more clearly and with greater sustain. Again, putting all build quality issues aside, the longer length allows for "more" of these characteristics. So does a well built 34" bass give you some of that? Yes! Does a well built 35" instrument give you even more? Yes, if the wood selection and components are the same. That's the tricky part, but it's just as tricky in building that perfect 34" instrument as it is in the 35" instrument. The end result is the same when speaking in generalities of the comparison.
Really folks, if you like 34" B strings, just go forth with them and be happy. They can sound and play great. But you can not say that build quality is all that is required to make a 34" scale instrument have the same feel as a similarly built 35" instrument. It's simply not possible within the laws of physics. That doesn't mean that a 35" bass is automatically better in any stretch of the imagination. Build quality and rigidity of the wood aside, both scales have strengths and weaknesses, so don't let someone tell you that one is better than another unless they are stating a personal preference.
At the same time, don't let anyone tell you that a 34" instrument can have the same tightness and clarity of a 35" instrument if they are truly built with the same exacting specs in every other regard. It's just not possible. Which ever one you like is all that matters.
And who says that piano like clarity is always a good thing? Having a shorter scale instrument can result in a more throaty, growly tone quite often, and that could be highly desirable. So less tension on the strings can be a good thing if that is what you are after.
Next time you are at a piano store, sit down a a full grand and then a baby grand. You can hear the difference. It exists in pianos, and it also exists in bass guitars. Sure it's only an inch, but it does change things a little bit.
