One rather pedantic clarification as to Jeremy's PHB quote: The actual italicization is as follows.
Familiarity: "Very familiar" is a place where you have been very often and where you feel at home. "Studied carefully" is a place you know well, either because you've been there often or you have used other means (such as scrying) to study the place.
That use of italics strongly implies that the text is referring to the actual
scrying spell, rather than "scrying-type" spells like
clairvoyance/clairaudience.
That aside, nharwell's interpretation is a nice rules-lawyering take on limiting the b-s-t tactic. Under his interpretation, effective use of the tactic would require expenditure of a 7th-level spell and 100 xp (
vision) to actually get the BBEG's location before teleporting in and ruining his day. My tendency, though, is to think that the designers intended the opposite: that the
scrying spell also discloses some details, however spotty, of the scried being's location. After all, the spell creates a sensor "near" the scried being, which might show enough of the surroundings to use
teleport without error, in any case.
Under my interpretation, we're back to house rules, sadly. It's worth noting that 2e (well, 2e FR material, anyway) was rife with spells and items that prevented or hindered teleportation. One might wish to reinstate those spells and items for 3e use. Another less obvious and frustrating counter-tactic is to use the opposed Scry check rules found on Andy Collins's website at
www.andycollins.net .
To answer the original poster's "poll": Yes, I do think the b-s-t tactic is problematic. IMC, everyone ends up running around with nondetection spells and items, and more powerful individuals have serious anti-teleport protection on their homes. But yes, it does come off somewhat contrived. D&D has this problem in general, though; the designers are good at limiting combat spells, but not so good with utility spells (look at poly other, for pity's sake!). Scrying and teleportation, IMHO, are two of the biggest problem areas (the third being easy resurrection). They aren't problematic in the sense of ruining the balance between PCs and NPCs, but rather in the sense of providing serious spoilers to campaigns that DMs are intending to resemble LotR more than JLA or
The Authority.