Ed,
In general, yes. and no. The recent Cape Hole discussions show that you can have a good par 5 (then in the 290 range, but now almost anything under 390) that is specifically NOT driveable.
But, if you want it driveable, make it driveable with an opening. That said, I recall seeing the 14th at Franklin Hills near Detroit, a 300 yard Ross Gem fully ringed with green side bunkers to prevent driving the green. Damned if some members don't just tee a driver high and still land tee shots on that green with some regularity! If you are worried about the very best players, you can eliminate the opening. If you are worried about the 3-15% or so who might be able to take advantage of a driveable par 4, by all means, leave an opening.
Its sort of the reverse of a bank building a safe but then leaving the door open, isn't it? I could think of many other examples, but you get the idea.