I, too, host my own MTA on a residential DSL line. However, I have a fully
functional rDNS on it was well. For those that cannot do this, I'd suggest
finding another ISP that allows this. Until consumers demand it, ISP's such
as yours won't go out of their way to provide this service.
That may be possible in some jurisdictions. In others, there is
a single dominant provider, and you get what they have to offer, and
that's it. For example, much of Europe is in this situation, and
there are now more Internet users over here than in the US.