Just playing devil's advocate here, but is the mix of punters and own-gunners that bad? After all, the US has a far larger (in percentage) group of people that make the transition from rental to own-gunner.
If they never saw people running around with their own gear, how would they even know it existed?
Fair questions. I'll try and answer without writing an essay...
Mixed groups of punters and own gunners is certainly a quicker way to capture the attention of those individuals you might want to take up paintballing as a hobby. It results in more awareness of the various types of paintballing activities available, so conversion rates are naturally going to be higher.
The flip side of mixed groups is the overall damage it causes to the grassroots of paintball - newcomers from the general public who are trying out paintball for the first time. Many "punters" will already be quite nervous about participating in their first paintball game, having heard stories about how much it hurts and possibly some worrying reports of badly run paintball venues.
These guys and gals go to their first paintball day and get mixed in with intimidating own gunners. Immediately their experience is compromised before they even start playing. Apprehension builds and many individuals will already begin to convince themselves that they are in for a bad experience. Then the games start and they are greeted with high rates of hire, experienced players who run rings around them, a reduced element of fun, an increased sense of seriousness, and an increase in number of hits they take.
The majority of people are not going to enjoy this experience.
The best form of marketing is word of mouth. It only takes one bad report to damage a businesses, or an activity's reputation. In the states, many new paintball sites have opened up on small areas of land, with their playing fields consisting of Sup'Air or "concept" arenas. Paint is sold comparitively cheap and mixed groups are common place. Suddenly, we have a large pool of people having poor first experiences at paintball venues. At best, they simply wont try paintballing again for several years. At worst, they will tell all their friends and familly about the crappy time they had playing paintball.
A better approach, in my opinion, is to provide a quality product at all levels. Ensure each individual has a fun, exciting, quality experience when they first try paintballing. Then educate those who show an interest in the game's various formats and local opportunities to get more involved. The conversion rate may be lower, but the pool of people who have had a great time paintballing and will visit a venue again within the next six-twelve months is higher. So is that pool of people discussing positive things about the game.
To sum up, catering to the newcomer to ensure newcomers have a good experience is a recipe for success. Focussing the public paintball product to own-gunners is a sure fire way to damage the industry. Activities should be seperate, but education about the various forms of paintballing should be encouraged.