This is sad but true. People shouldn't commit to adopting an animal if they're not prepared to take care of it for life.
It's also sad when you go to an animal shelter it's almost all Chihuahuas and pit bulls.
Yes, it should be a lifetime commitment. At the shelters here, usually a lot of pits and pit mixes. The smaller dogs, especially the ones that don't do ok in the shelter, will go to various local rescues fairly quickly. There have been some Malteses, Yorkies, Shih Tzus, and other smaller breeds and it is possible to get one if someone is persistent and the timing is right. I do think the pits get an undeserved bad rap and they can be great dogs if given a chance.