There's not a thing wrong with relying on a small amp for a long time. When you're just starting out, there's no need for a huge rig, even with your first couple of bands that you may find yourself in. Of course, most kids starting out have no concept of playing quietly or dynamics, so there often is a false 'need' for a large rig to compensate. Once you discover that loud is not necessarily always better, you can make do with a smaller rig and be very happy.
I've never had a need for a super big rig, and have always believed smaller/simpler is better. I rarely find myself in situations where I need a TON of power, and I am always trying to keep onstage volume at a minimum for the sake of the band. I played all through college and for quite a few years after with only an SWR Workingman's 12 combo and a 1x10 extension cab, playing jazz on electric and upright, and also doing the occasional singer/songwriter gig. In the last 3-4 years I moved back to playing electric bass in more pop/rock settings and needed to punch up my sound/presence a bit more. I have since augmented my setup with the following:
SWR Workingman's 2004 head
SWR Workingman's 1x15T
SWR Workingman's 2x10T
About 3 weeks ago I bought an Eden Nemesis NA320 head that I use with either or both of the SWR cabs because the SWR head wasn't cutting it on some gigs. I didn't want to go crazy, and the NA320 gave me the power and sound I wanted with my existing cabs. I swear, there's a lot of power to be had in a setup like that. Any more power than that, and you begin to piss off the sound guys and your bandmates. If you need to hear more of YOU, get yourself in the monitors.
The point of all this is that once you get established and start gigging in larger situations, the smaller combo may not necessarily be enough, depending on the style. However, a huge rig is not necessary either. A nice, powerful 2x10/head combo or similar setup will get you through most normal situations with comfortable clarity and presence. Three cheers for SMALL rigs!