While I don't think it is nice to make anyone feel unwelcome especially at a support group I would try to be generous to those with PPMS.
You may remember Brenda B from another board. We were both diagnosed at the same age, same month and joined the message board at the same time. Sadly MS robbed her of her life very quickly. Within a few years she had to attend adult day care and she disappeared from cyber space. In the same years I was blessed to be able to continue working full time and attend school full time as I carved out a more MS friendly career.
It is the luck of the draw but my heart goes out to all of those who weren't as "lucky" as I have been. My God I hate this disease no matter what subtype.