Being only a semi-traditionalist I can appreciate the use of all tartans and kilts. However, I feel that so many "clans" aren't clans anymore - and therefore a name is just a name.
For example, my surname is carried over from a female bloodline. So I will never know my "proper clan" unless I find out who my grandfather's father was. Even then I wouldn't feel a proper connection - and wouldn't feel correct wearing the associated tartan of that clan (if there was one).

Many people understand a Scottish-Irish connection to be extreme and the two terms are almost interchangeable. For parts of Scotland - such as the Gaels I would agree that there is a great Irish connection, just as there are many Irish immigrants throughout Scotland, though, specifically in the West in recent decades. Many of the Scottish clans are formed around Irish surnames.

As far as solid colour tartans, my personal view is that as long as someone is wearing A kilt and wearing it well I can appreciate the action. My opinions follow onto non-Scots tartans, where I believe that if a tartan symbolises something - even just the person liking the design, then they have a personal right to wear it. However, I can appreciate when traditionalists will state that those of only a direct connection should wear it. As far as universal tartans, I think they're great. I don't think anyone could argue about someone wearing the Scottish National simply to honor Scotland, even if they have no direct connections to our country. I love the idea of modern district tartans as people can very much associate with them - as we regularly witness on the forum.

To summarise - if anyone wears a kilt, I'm happy that they're wearing a kilt. As far as tartan history, fashion tartans, solid colours go; as long as they're happy with it then I'm happy with it!