Limiting build time from 5 hours to 1 hurts some open source projects

Limiting build time from 5 hours to 1 hurts some open source projects.

Should it be limited by CPU cycles usage instead?

My project builds whole OS linux image for arm processors. Open Source, Free.
I used to be able to get few builds a month taking close to 5hr each.
Now with 1hr limit it’s impossible.

Why circleCi care so much about limit build time? There could be one 5hr build a month or
100 under 1hr builds a month. Looks like second case is allowed but first is not.

Thanks