But on premium cable (especially HBO, but also Showtime -- not sure if Starz has gotten into the business yet) the TV movie is an important and growing part of programming.
Maybe, but I see that as being almost a different medium. Premium channels aren't necessarily available to the same audience as commercial or basic-cable networks, due to the cost. And the style and content of the programming tends to be different.
What I miss are things like the TV movie series we used to have, things like Columbo or the '80s Perry Mason revival. I always thought that would be a good format for Star Trek, a way to get more stories per year than feature films would allow with a higher budget than weekly TV would allow. It could've been a good format for SFTV in general, but we rarely got any series like that. There was the Universal Action Pack including Hercules: The Legendary Journeys and TekWar, but both of those went to weekly series a year later. And the original Battlestar Galactica was intended to be a series of 2-hour movies, but the network insisted on retooling it into a weekly series (which is why it had so many 2-part episodes and why the 1-parters, which were written in haste when the decision was made, are so weak in comparison).
For some reason, over the decades, broadcast TV has gotten more and more limited in format. In the early days, in the '50s, there were shows that lasted 15 minutes or 45 minutes; and from then through the '70s there were frequently shows that ran 90 minutes. But eventually those faded out in favor of a more standardized selection of half-hour sitcoms, hourlong dramas, and 2-hour TV movies, plus miniseries emerging as a format in the '70s and '80s. But these days network TV doesn't have movies or miniseries at all anymore, and basic cable only infrequently does. It's odd that the options keep narrowing.