These are my suggestions to meeting participants in general and architects and senior developers in particular:
- Give your colleague's idea 5 minutes. It could very well be the ide has merits you don't see. Letting the idea float for a couple of minutes before you shoot it down does not mean you endorse it.
- Appreciate that there are no perfect solutions, all approaches come with their own set of advantages and disadvantages. Thus, make the meeting a safe place where people can share their ideas and voice their thoughts.
- Don't interrupt
- Don't laugh at your colleague's arguments.