holodecks are very interesting concept, but the way they were displayed is not very credible.
I can admit that it can imitate objects.
But how can it simulate such a large space.
In "Take Me Out to the Holosuite" the holosuite creates a baseball field, sisko watches the others playing while sitting on the arena.
I seems the real people in a holoprogram can be 50 meters from one another, perharps much more. While the same holosuite, when turned off, is only ten meters or so wide!
I really cant think of how that is possible.
Second, how did they not improve the safety. In at least half a dozen occasion, a holosuite problem put the whole ship in jeopardy.
Realistically, starfleet would either improve the safety greatly or remove the holodecks from ships.
What navy in the world would tolerate a reacreationnal technology that occasionnaly endangers a ship ? Then again, it's not only recreationnal, it's also a training ground for about anything.