Architecture is often treated with neglect, and even disdain. While such attitudes are unfortunate, they are not hard to understand. Architecture is a long-term concern. Indeed, an immature architecture can be an advantage in a growing system because data and functionality can migrate to their natural places in the system unencumbered by artificial architectural constraints. Premature architecture can be more dangerous than none at all, as unproved architectural hypotheses turn into straightjackets that discourage evolution and experimentation.
Architecture is expensive, especially when a new domain is being explored.
Getting the system right seems like a pointless luxury once the system is limping well enough to ship. An investment in architecture usually does not pay off immediately. Indeed, if architectural concerns delay a product's market entry for too long, then long-term concerns may be moot. It's hard to recover the value of your architectural assets if you've long since gone bankrupt. Programmers with the ability to discern and design quality architectures are reputed to command a premium.