This is an overused excuse that's not a barrier to running a mail server.
If your server's network has a bad reputation and is on blocklists, there are other options. You can find a reputable mail provider and smarthost through them. You can smarthost through a friend's server. You can purchase a cheap VPS and smarthost through that.
The point is that all the advantages of running your own server (or as many of them as you care about) are all still there. For instance, you can have real, physical possession of your data, keeping it out of the hands of unscrupulous corporate entities that'll sell your data for pennies. You can decide precisely who and how to block. You can have full logs of all attempted deliveries, both from you and to you. Smarthosting takes none of that away.
