Yeah, but a systematic nerf(i.e. changing teleport to work like this so its harder to get to a place you hadn't actually been to) is more consistent than using teleport blocks, diverts and special locations all the time.
And then the players pull out the scrying and background stories on how they traveled the whole world (just like the druid knows every animal out there), and suddenly your nerf is no more.
One of the biggest problems with D&D it's that there's plenty of ways to go around suposed drawbacks. Thus such a "change" like you sugest doesn't really do much because the players who want to teleport directly just do a little scrying/knowledge checks and be good to go.
On the other hand, teleport comes with a
built-in drawback that has no workarounds whatsoever. Really, why don't use it? Heck, you can even let the players use divination and knowledge checks in advance to know to where they can teleport or not! What's exactly the problem for using the actual rules?
After the second time it fails because of 'special location' bullshit, yes, I'll have figured out its the latter. I'll also be pissed with the GM for not mentioning it.
Let me see if I understand, reading only the part that of the spell that's usefull to you it's all fun and games, but the DM enforcing the spell to work by it's actual rules it's bullshit?
So, do you also call bullshit that your caster can't use cast spells when he runs out of slots? Or that you die when you reach -10 HP? Or that you'll only reach lv 3 when you get 3000 exp total?
The DM's job is to provide challenges for the party, not to let them do as they please while ignoring the rules that aren't convenient for them at the moment.