Simply put, they're expensive.
Lulzbots are some of the most durable, reliable machines on the market. The company's been making them longer than most other entrants to the field and have a time tested design they iterate on slowly to maintain the stability that's expected of their brand while adding features customers come to expect from the market. They refuse to compromise on just about any component, and by doing so aren't as competitively priced as other options for the average hobbyist in regards to features available. However, I've seen a number of small manufacturing outlets, schools, labs, and other places that need a true workhorse rely on Lulzbots to form the backbone of their printing needs.
I'm aware that sounds like a shill post, but I feel the need to mention it's not. If I were a shill for Lulzbot, I'd at least ask to be paid with a Lulzbot for my efforts. That said, /u/jebba, offer's on the table (kidding, unless you are willing to send me a Taz 6 with dual extrusion in exchange for me writing nice things about it, in which case I am absolutely not kidding)!