If the premise is that there is no value to be added from startups seeking high growth from surrounding yourself with other startups, then I have to disagree.
Sure, you won't get high growth if you spend all your time hanging with brogrammers and drinking at industry social events. But learning from smart people is something that happens almost by osmosis if you mix with a good selection of other startups.
Being around when one startup falters and the founders and team are looking to join something interesting means your network for recruiting grows, and some of the best team mates I've had have been when one startup died and folks joined up for another. That's accelerating growth.
Seeing what mistakes others are making prevents you from making and short cuts the path to making the right choices. That's accelerating growth.
If you've got a crappy product and an idea that isn't going to work, and you spend yourself hanging out with others similar to you in that, well, you're not going to do anyone any good. Particularly not when, as I've seen, it becomes a complaint fest about the industry not an analysis of what you could be doing better. Like anyone who's ever worked at a big company will tell you, if you hang outside the building with the smokers bitching about the company, don't be surprised if you aren't the ones doing well at that company.
So YMMV, but absolutely mix with other startups. Pick well who your friends, mentors and models are. It's unlikely that it's going to hinder your growth, unless your attitude was such that you probably weren't going to get that growth in the first place.
"Our startup, Kip Solutions, is a social media consulting firm for social causes."
With all due respect, if you were pitching your social media consulting services to startups, it's very likely you were put on the same list as recruiters.
Unless you are selling to startups as your market, you have to get out of the startup echo chamber at some point, and get out in the trenches where your customers live, and talk to them. If you're selling to manufacturers, instead of going to the nth "startup happy hour" even of the week, how about go the "National Manufacturers Association" trade show or whatever?
On a related note, we should look at our social media activity and ask who our audience is... the HN crowd, and other startups, or customers? Personally, this is something I've just forced myself to start looking at differently in the past 2 weeks or so. I've cut back on tweeting tweets about startups and VC and Silicon Valley gossip, and started tweeting stuff that's, ya know, of interest to the people I want to sell to. It's a seemingly subtle change, but in just two weeks we already have dozens of new followers who represent our potential customer base. That's "permission marketing" at work, and it's something I wish I'd realized a lot sooner.
Anyway, I think the OP is onto something. No, don't take anything as an absolute... and go to the "startup happy hour" from time to time, sure. But don't forget to take time to go talk to customers (or potential partners, suppliers, resellers, etc. Whoever you need to connect with in order to advance your business).
