I'm with you there, I hate seeing porches that have been enclosed.I have been working for over a year on making a very poorly built sun room into something respectable. I would prefer having an open porch versus a room at all.
The people in RT's house before us converted a garage to a play room but did a crap job and the HVAC isn't properly sized to heat/cool the space adequately. They also removed the door between the dining room and garage. The room is awkward and RT said she'd rather have a garage to store things in. Curiously they left the garage door in place, hopefully the tracks are still there under the drywall.