As case for monitors:
Love TL, but too much can overload your room (had monster/great TL's 30 years ago that only sounded good in 20,000 cu. ft.). Note that TL monitors exist (that sound extremely good).
According to Floyd E. Toole (recommend reading 'Sound Reproduction') in-room bass can only done correctly with multiple subwoofers spread around the room (search AC for 'swam').
"Only done correctly" I think is an exaggeration of what Toole intended. I doubt Mr. Toole would say people listening to a pair of tower speakers are "doing it wrong". He was primarily focused on obtaining an even bass response at all listening positions in a room, which doesn't necessarily apply to rooms setup primarily for one or two listeners.
For many, having a less than flat bass response is an acceptable trade-off for eliminating the expense, added complexity and aesthetic issues subwoofers present. In many rooms is possible to get a reasonably flat bass response at the primary listening position without subwoofers, especially if you use some sort of room EQ (although flat response around the entire room is admittedly more difficult).
In terms of the OPs question of Towers vs Monitors, using Tower speakers doesn't eliminate the possibility of adding subwoofers. In some rooms the option of a lower cross-over point may be an advantage, and a larger cabinet often brings greater efficiency. In the case of Salk speakers, the beautiful veneer work just doesn't look as impressive on a monitor as on a tower.
That being said, I love my two Salk Subwoofers. I just wouldn't go so far as to say monitors + subs it is the "only correct solution" for 100% of listeners and rooms.
As in all things there are trade-offs and compromises.
