I did a lot of plumbing at my last job, and let me say, no one should WANT a garbage disposal in their house. The reason that law is in place is so that when you clog up the sewer and your house floods with $h1t water, then it is all your fault/expense to fix - the city is in no way liable. And also most flood insurance does not cover self-induced flooding...
pipes are made for water, and sewers are made for water, human waste, and toilet tissue - nothing else...
People dump all kinds of crap down their drains/flush it down the toilets, and just assume it magically goes away...
Heck, clean out the trap under your bathroom sink sometime, see all the sludge just from toothpaste/hair/soap, and then imagine what would happen if you started putting food scraps through...not to mention flushing big chunks of tampon/condom/those"disposable" swiffers, etc...
just a little rant. You'd be amazed at how nasty drains get very quickly...