TV viewing as we know it will be taking the route of the landline in a few years. Taken over by streaming services through high speed internet.

If it happened as much as you say (EVERY TIME IT RAINS) your dish needed to be reaimed. Had it for many many years and did on occasion lose signal but rarely and def not even close EVERY TIME it rained. It survived hurricane Sandy up north with maybe 15 mins of LOS and no LOS during IRMA here. I would re-aim it when I saw signal degrading and it was good again until my mower wacked the mounting pole a few times. I eventually cancelled it because I had to start paying for it as it was 90% free since I had worked for them.

I’ve left the up on roof in last 4 homes
 

can’t think of any reason for taking it down

Generally not, but they are made of metal and they are usually poorly grounded by the installer. Also they aren't attractive especially if you have no need for it and they can rust (older ones) and can become a sail in hurricane winds and don't fly very stable. During our training, which was well after Andrew, we were shown (poor) installations at Homestead air base (we were DirecTV MDU providers there and a few properties in Broward) and the end results.

I went through a few killer hurricanes on coast, no problem there’s one on a house in Miami I sold to cousin long ago it’s still working, as for the way they look I don’t even notice it in back of roof . Taking it down seems to me to invite a problem where there is not one now , I hear the same thing about solar tubes which I’ve been using in last 8 homes , contrary to what people say they never leak and they don’t cause extra heat

When you remove a sat dish from a roof you leave the flat steel mounting base so there is no further roof incursion (or problems) then there was when it was installed. You are correct that if removing the base and not sealing properly can lead to issues as well as damaged shingles that can break up. Plus, since the base is generally universal it can be reused without creating further damage to the roof should one want to sub again.