On the contrary, dynamic are usually more suitable for drums (exc. cymbals and sub-kick) because they're more suitable to mid-range, and high-SPL (sound pressure level) instruments. Plus they're cheaper. I mean, you can close-mic drums with condensers, but it's not very often people do it, and most condensers can't handle the SPL. You usually use them for cymbals and overhead / room microphones.

Dynamic microphones work fine for close-micing trombone. Especially in this context. The usual microphones I use if they're on a stand, are microphones like the SM57/57, RE20, MD421/441, which are all dynamic.

Probably wouldn't use them in a "classical" context, or sometimes studio-type jazz context, that's where I'd be more likely to be using a condenser (e.g. u87 / 414) or Ribbon (R121 / Coles 3048). You want to allow the sound to develop in this context, so the room is quite important, and part of the mic'ing is capturing the reflections from walls and materials around you, and therefore these mics are probably more likely to be used omni-directional (as opposed to cardioid / super-cardioid dynamic).

Also, you can have small and large diaphragm mics on both dynamic and condenser. Basically the larger the diaphragm is, the better it is for capturing low frequencies. Smaller are usually suited for higher frequencies. That's why stuff like the 421 / RE20 are great for trombones (they're large-diaphragm dynamic microphones), you might also see people using "kick drum" microphones like the d112 or the shure beta 52 on bass trombone. (I honestly have no idea how this applies with small clip on microphones, though... must be magic.)

Either way, it's not really as such that, they don't bother making microphones specifically for trombone, it's just that they're usually multi-purpose, so there's not really much need for it.

(I'm no expert btw, that's just my understanding and take on it. Also, not trying to sound condescending, might be interesting for someone. I just like typing, apparently.)