To somewhat disagree, the Wii lacked the staying power I think of the other consoles because of the low end hardware it simply couldn't keep up with where software was going.
The resulted in fewer ports.
Plus if you compare the Wii ecosystem to the 360/PS3, the install base on the latter is much larger and the systems are more similar from a user POV. It's worth it just port between those two while the Wii isn't really worth it.
You're right, but I don't think that's the full picture. Even if the Wii was up to performance with the 360/PS3, there still wouldn't have been many ports because they cater to fundamentally different gameplay. Most Wii players never owned the gamepad, only the Wiimote and nunchuck combo.
I think the Wii's problem was only partially related to its performance, and much moreso related to the fact that motion gaming was a fad that ran aground fairly quickly.
It wasn't just the Wii either, remember when the iPhone came out and developers imagined a crappy future where you'd practically fall out of your chair playing a racing or flying game.
Once the novelty of Wii Sports wore off, the Wii was dead in the water. The DS in contrast was a much stronger, much longer-lasting platform that could keep its player base interested for more than a few months.
The resulted in fewer ports.
Plus if you compare the Wii ecosystem to the 360/PS3, the install base on the latter is much larger and the systems are more similar from a user POV. It's worth it just port between those two while the Wii isn't really worth it.