Why so long before you can upgrade your mech in any meaningful way?

[Kimbrown]

I've only been playing ItB for a couple days now, and am very impressed (as I was with FTL). The tactical play is incredibly tight but I'm a bit less impressed (I'll say confused at this point though) with the mech development. Since I know Subset puts a lot of thought into their games, I'm wondering if I'm missing something and if not, what they're reasoning was on some design choices. The thing that seems strangest is that you have to fight a whole island before getting any upgrades (except for pod drops). If you were to close out the game after two islands that means you've spent almost half the game with default mechs. Why didn't they make a shop always available so you could upgrade when you had the rep? And if that would create difficulty scaling problems, why not have an initial store so your mechs could instantly have some differentiation? It also seems odd that there wouldn't be a default amount of reputation on island completion so you could at least get something. I'm not complaining at this point- just curious to hear your thoughts on the design decisions.