They often let programmers proceed at their own pace. Strict standards or practices are not going to get in the way of someone who likes to code.
Cons
There are few to no best practices, which leads to mistakes and problems that could have been avoided. No code standards or code reviews means a code base that is non-standard and limited by each developer's understanding of good practice. Products are well out of date. Employee development was non-existent until just recently. No marketing means that future efforts are often a knee jerk response to sales and rarely fill out the product offering well. Still in existence because lives in such a niche market.