Was it only the license fees or the fact that (for the time at least) it required powerful hardware ?
For example, if memory serves me right, at the time of the introduction the LaserWriter had a more powerful cpu than the Mac that it was supposed to go with.
Yes, until about 1995, a new laser printer could have a more powerful CPU and more RAM than a fairly common (even new) office computer driving it. That stopped at about Pentium 100 speed and 6 MB of RAM because normal use cases didn't need more than that.
The original Apple LaserWriter had a Motorola 68000 CPU running at 12 MHz, 512 KB of workspace RAM, and a 1 MB frame buffer. That wasn't cheap, but Adobe's pricing of the PostScript license was still very steep and contributed significantly to the high printer costs. Adobe's greed over licensing fees caused serious conflicts between Apple and Adobe.
To give people an idea: that's 3x the RAM and about 2x the CPU power of the contemporary Macintosh (512k of ram (not expandable), and a 7.8MHz).
It wasn't until the Macintosh II came out that there was a mac that was strictly more powerful than the LaserWriter, and by then the LaserWriter IINTX was available; similar CPU to the Mac II, but more base memory and could be expanded to more total memory.
I know that it added a great deal to the price of printers, if I got them with actual (as opposed to emulated) PS.