I think the difference is size over here can be simply measured:
Noise band of any scale. Be it small or be it legendary "founding fathers of genre", you have less people than punk show or any band really? As I mentioned, I feel punk is even more of social network and lifestyle as well as bar background music. Weekend punk gig in helsinki - you got bar full. I assume regardless who plays. It's about hanging out amongst many other things.
To me, it is perfectly healthy situation, that noise would remain genre of fanatics. The same guys who buys, listens and makes noise, visit the shows. Added with some curious visitors and live sound appreciating people.
I don't think it's needed that one values live moment based on how many bar regulars or how many people who don't give a fuck happen to be around making crowd appear bigger than it really is.
I have played noise for audiences ranging from... I guess 1 to c. 300 ? I don't think it mattered much which size audience there was.
I think one of the reasons could be that a lot of noise shows are better as idea than as reality. Most often you compromise with volume, technical aspects such as being unable to fully do your best in live situation, visual dullness (mentioned computer live gigs etc), and so on. When all elements work, noise shows are great and most likely could attract more crowd.
But if all elements are compromised, you know it COULD be great, but.... under the circumstances, only in your own mind. For anyone curious or half-interested it might appear as "is THIS it?!" Seen so many noise shows which surely ain't representative of what really good live show is.
You can ask did the artists bother to rehearse their possibilities to perform loud live noise? Have the organizer or bands brought enough amp power? Is the soundman cooperative or trying to sabotage entire evening. Is the visual presentation a man in bar corner with macbook in his lap? And so on...
Noise shows with zero budgets, there's very little to do.
I guess the healthy thing has been in Finland the established SICK network which is suitable to co-operate in matters of organization, promotion, amps, video technology and such. Making it little bit easier to pull out shows which attract 30-100 people without it all being one guys personal sacrifice of funds, energy and time. Now it's more collaborative effort, where ideas can be realized pretty decently. Although one could say it's still live & learn situation.
Talking of that, Finns can next time enjoy live noise in Helsinki 20.4. bunker (Roman pilates (canada harsh noise), Umpio, Halthan) and then followed by.. was it 25.5. lepis (grunt, bizarre uproar, etc). I guess advertising happens when all 100% confirmed.