It's not about having 'yes' people
I've worked with an engineer who's negative attitude really caused problems, not least because many of his "it can't be done" statements were not true.
In one case we'd built a SAP installation server to roll out the client to around 3000 users.
This engineer asked how we were going to do the roll out so I told him. His immediate response was "that doesn't work" which was pretty odd because by that time we'd already done our first 100 installations using it.
The other thing that was especially trying about him was he would always bring problems, but never any suggestions for solutions, work arounds or alternatives. He'd just label something as unsolveable and then drop it at your feet like a cat delivering a dead bird. Worse still he seemed to derive pleasure from the process.
There aren't always solutions to particular problems but if you can show you've looked into them and considered alternatives or work arounds it shows a more positive approach.
I don't want yes people on the team but I do want people who don't simply stop when they find a problem.
Taking the excel or access data warehouse problem as an example which would you prefer to see?
1. It can't be done
2. It can't be done with excel or access but you might want to consider these alternatives
I know I'd certainly prefer option 2.