Costs grow exponentially with the size of the WordCamp. At a certain number of attendees, the WordCamp model could potentially stop working.

A WordCamp for 100 is almost free to organize, one with 200 will need a sponsor or two to help with paying the bills for t-shirts and speakers dinner. Almost no fixed costs at this point. One with 400 needs a paid venue, probably money for equipment, has many volunteers and speakers. One with 1000 requires very serious and early commitment - some of the organizers are almost full time for months, large fixed costs need to be paid as early as a year in advance. With 2000 the process is longer than a year, involves multiple external contractors, and is even more expensive.

If we put things in that perspective, we should only do small to medium size WordCamps so that we don't leak money from the IT industry to the travel & entertainment industry for overpriced accommodation and outrageously expensive venues.

However, WordCamps are not sponsors driven, they are community driven. Many of the WordPress professionals, software engineers, bloggers, business owners seems to enjoy gathering together for WordCamps every year and this seems to keep happening even when very important individuals or companies step back.

I have huge respect for what you do at Sucuri and I hope that your company keeps doing a good job no matter if you keep your involvement in conferences or not. There are many other ways to contribute to Open Source.